subject-chemistry term-1 session 2021-22

STUDENT SUPPORT MATERIAL SUBJECT-CHEMISTRY

TERM-1

SESSION 2021-22

STUDENT SUPPORT MATERIAL

CHIEF PATRON

Dr. JAIDEEP DAS,

DEPUTY COMMISSIONER,

KVS AHMEDABAD REGION

PATRON

SMT. SHRUTI BHARGAVA,

ASSISTANT COMMISSIONER,

KVS AHMEDABAD REGION

UNDER THE SUPERVISION OF

SHRI MANISH JAIN,

PRINCIPAL, KENDRIYA VIDYALAYA ONGCANKHLESHWAR

CO-ORDINATION TEAM

PHYSICAL

CHEMISTRY

ORGANIC

CHEMISTRY

INORGANIC

CHEMISTRY

SH. P K PATIDAR,

KV ONGC

CHANDKHEDA

DR. M R CHOUDHARY,

K V SAC

AHMEDABAD

MRS. SABIHA SHAIKH,

K V No.1

SURAT

REVIEW COMMITTEE

PHYSICAL

CHEMISTRY

ORGANIC

CHEMISTRY

INORGANIC

CHEMISTRY

QUESTION

PAPER

SH. BHARAT KUMAR

PANDYA, K.V NO. 3

SURAT

SH. S. K. SONI,

KV AHMEDABAD CANTT

SH. ATUL TIWARI,

KV 2 EME BARODA

SH. INDRA MAL,

K V INS VALSURA

CONTENT DEVELOPEMENT TEAM

CHAPTERS NAME

NAME OF TEACHER

NAME OF SCHOOL

1. SOLID STATE MRS ANJU BALA KV NO-1,SHAHIBAUG AHMEDABAD

2. SOLUTIONS MRS REENA TIWARI KV CRPF GANDHINAGAR

3. p-BLOCK ELEMENTS SH. S. C. YADAV KV ONGC ANKLESHWAR

4. HALOALKANES AND

HALOARENES MRS NAGESHWARI KV AFS MAKARPURA

5. ALCOHOLS, PHENOLS

AND ETHERS

MRS BABITA NIGAM KV -02 KRIBHCO , SURAT

6. BIOMOLECULES SH. RAJ KUMAR MEENA NO-2 INF JAMNAGAR

7. QUESTION PAPER SH. J L AGARWAL KV SHAHIBAUG AHMEDABAD

4

CHEMISTRY Class-XII

INDEX

S NO CONTENT PAGE NO

1 SYLLABUS THEORY TERM-1 2-3

2 SYLLABUS PRACTICAL TERM-1 4

3 THE SOLID STATE 5-14

4 SOLUTION 15-23

5 THE p- BLOCK ELEMENTS 24-34

6 HALOALKANES &HALOARENES 35-47

7 ALCOHOLS, PHENOLS &ETHERS 48-58

8 BIOMOLECULES 59-68

9 CBSE SAMPLE QUESTION PAPER 69-84

10 SAMPLE PAPER 85-93

5

SYLLABUS FOR SESSION-2021-22

CLASS XII Term-I S.No UNIT Periods MARKS

1 Solid State 8

10 2 Solutions 8

3 p-Block Elements 7 10

4 Haloalkanes and Haloarenes 9

15 5 Alcohols,PhenolsandEthers 9

6 Biomolecules 8

TOTAL 49 35

Solid State: Classification of solids based on different binding forces: molecular, ionic,

covalent and metallic solids, amorphous and crystalline solids (elementary idea).Unit

cell in two dimensional and three dimensional lattices, calculation of density of unit cell,

packing in solids, packing efficiency, voids, number of atoms per unit cell in a cubic unit

cell, point defects.

Solutions: Types of solutions, expression of concentration of solutions of solids in

liquids, solubility of gases in liquids, solid solutions, Raoult's law, colligative properties -

relative lowering of vapour pressure, elevation of boiling point, depression of freezing

point, osmotic pressure,determination of molecular masses using colligative properties.

p Block Elements: Group -15 Elements: General introduction, electronic configuration,

occurrence, oxidation states, trends in physical and chemical properties; Nitrogen

preparation properties and uses; compounds of Nitrogen:preparation and properties of

Ammonia and Nitric Acid.

Group 16 Elements: General introduction, electronic configuration, oxidation states,

occurrence, trends in physical and chemical properties, dioxygen: preparation,

properties and uses, classification of Oxides, Ozone, Sulphur-allotropic forms;

compounds of Sulphur: preparation properties and uses of Sulphur-dioxide,

SulphuricAcid: properties and uses; Oxoacids of Sulphur (Structures only).

Group 17 Elements: General introduction, electronic configuration, oxidation states,

occurrence, trends in physical and chemical properties; compounds of halogens,

Preparation, properties and uses of Chlorine and Hydrochloric acid, interhalogen

compounds, Oxoacids of halogens (structuresonly).

Group 18 Elements: General introduction, electronic configuration, occurrence, trends in

physical and chemical properties,uses.

HaloalkanesandHaloarenes: Haloalkanes: Nomenclature, nature of C–X bond,

physical and chemical properties, optical rotation mechanism of substitution reactions.

Haloarenes:Nature of C–X bond, substitution reactions (Directive influence of halogen in

monosubstituted compounds only).

Alcohols,Phenols and Ethers: Alcohols: Nomenclature, methods of preparation,

physical and chemical properties (of primary alcohols only), identification of primary,

secondary and tertiary alcohols, and mechanism of dehydration.

6

Phenols: Nomenclature, methods of preparation, physical and chemical properties,

acidic nature of phenol, electrophilic substitution reactions, uses of phenols.

Ethers:Nomenclature,methods of preparation,physical and chemical properties, uses.

Biomolecules: Carbohydrates - Classification (aldoses and ketoses), monosaccahrides

(glucose and fructose), D-L configuration

Proteins -Elementary idea of - amino acids, peptide bond, polypeptides, proteins,

structure of proteins - primary, secondary, tertiary structure and quaternary structures

(qualitative idea only),denaturation of proteins.

Nucleic Acids: DNA and RNA

***********************************************

7

PRACTICALS

TermI:

A 15 mark Practical would be conducted under the supervision of subject

teacher/internal examiner. This would contribute to the overall practical

marks for the subject.

OR

In case the situation of lock down continues until Nov-Dec 2021, a Practical Based

Assessment (pen-paper) of 15 marks would be conducted at the end of Term-I at the

school level and marks would be submitted by the schools to the Board. This would

contribute to the overall practical marks for the subject.

Evaluation Scheme

S.No Practical Marks

1. Volumetric Analysis 4

2. Salt Analysis 4

3. Content Based experiment 2

4. Class record and viva(Internal Examiner) 5

TOTAL 15

(1) Volumetricanalysis(4marks)

Determination of concentration / molarity of KMnO4 solution by titrating it against a

standard solution of:

i. Oxalicacid,

ii. Ferrous Ammonium Sulphate

(Students will be required to prepare standard solutionsby weighing themselves).

(2) Salt analysis (Qualitative analysis) (4 marks)

Determination of one cation and one anion in a given salt.

Cations- Pb2+, Cu2+, As3+, Al3+, Fe3+, Mn2+, Ni2+, Zn2+, Co2+, Ca2+, Sr2+, Ba2+,

Mg2+, NH4+

Anions–(CO3)2-,S2-,NO2-,SO32-,SO42-,NO3-,Cl-,Br-,I-,PO43-,C2O42-,CH3COO-

(Note: Insoluble salts excluded)

(3) Content Based Experiments (2 marks)

A. Chromatography

i. Separation of pigments from extracts of leaves and flowers by paper

chromatography and determination of Rf values.

ii. Separation of constituents present in an inorganic mixture containing two

cations only (constituents having large difference in Rf values to be

provided).

B. Characteristic tests of carbohydrates, fats and proteins in pure samples and their detection in given food stuffs.

8

1. SOLID STATE SECTION-A

CASE STUDY BASED-MULTIPLOE CHOICE QUESTIONS (I)

1.Read the passage given below and answer the following questions:

Solids are substances which have fixed shapeand volume. they are characterised by rigidity,

incompressibility, slow diffusion and mechanical strength. They are classified as:

(a) Crystalline solids

(b) Amorphous solids

(a) Crystalline solids - A crystalline solid is a substance whose constituent particles possess

regular orderly arrangement e.g. Sodium chloride, sucrose, diamond etc.

The crystalline solids are further classified as:

(a) Metallic solids

(b) Ionic solids

(c) Covalent solids

(d) Molecular solids

(b) Amorphous solids -An amorphous solid is a substance whose constituent particles do not

possess a regular orderly arrangement e.g. glass, plastics, rubber, starch, and proteins.

Q.1 Amorphous solids

(A) have sharp melting point.

(B) undergo clean cleavage.

(C) have regular geometry.

(D) are isotropic in nature.

Q.2 Which of the following solids is not crystalline?

(A) copper

(B) sodium chloride

(C) diamond

(D) Glass

Q.3 Which of the following statements regarding covalent solids is incorrect?

(A) They are very hard.

(B) They have very high melting points.

(C) They are good conductors of heat

(D) They have high heats of fusion.

Q.4 Dry ice is a

(A) molecular solid

(B) ionic solid

(C) atomic solid

(D) metallic solids

9

Q.5 quartz is a

(A) ionic solid

(B) covalent solid

(C) atomic solid

(D) metalic solid


An ideally perfect crystal is one which has the same unit cell and contains the same lattice points throughout the crystal. The term imperfection or defect is generally used to

describe any deviation of the ideally perfect crystal from the periodic arrangement of its constituents.

If the deviation occurs because of missing atoms, displaced atoms or extra atoms, the

imperfection is named as a point defect.

Such defects can be the result of imperfect packing during the original crystallisation or they

may arise from thermal vibrations of atoms at elevated temperatures because with increase in

thermal energy there is increased probability of individual atoms jumping out of their positions

of lowest energy.

Type of point defects – point defects in a crystal may be classified into three types

1.Stoichiometric defects

2.Non – stoichiometry defects

3.Impurity defects

Q.1 Which of the following defects is not a type of Stoichiometry defects ?

(A) Vacancy defect

(B) Interstitial Defect

(C) Schottky defect

(D) Metal excess defect

Q.2 In which of the following defects equal number of anions and cations are missing

from lattice site?

(A) Vacancy defect

(B) Interstitial defect

(C) Schottky defect

(D) Frenkel Defect

Q.3 Which of the following defects does not cause any change in density of crystal?

(A) Vacancy defect

(B) Interstitial defect

(C) Schottky defect

(D) Frenkel Defect

10

Q.4 In metal excess defect, the sites occupied by the extra electrons are known as –

(A) f- centres

(B) vacant site.

(C) interstitial site

(D) site of defect

Q.5 Which of the following compounds does not show metal deficiency defect?

(A) FeO

(B)FeS

(C) NiO

(D) NaCl


A regular three dimensional arrangement of points in space is called a space lattice or crystal lattice. There are only 14 three-dimensional lattices known as Bravais lattices. The basic difference between the 14 Bravais lattices are the angles between the faces and the relative

proportion of the sides. A unit cell is the smallest unit of the crystal which when repeated again and again gives the

crystal of the given substance. There are three types of unit cells based on the cube. These are: (a) Primitive or simple cube (b) Body-centred cube (c) Face-centred cube

Q.1 The coordination number of each atom in body centred cubic unit cell is

(A) 12

(B) 6

(C) 8

(D) 4

Q.2 In face-centered cubic unit cell, edge length is-

(A) 4√3r (B) 2√2r (C) 2r

(D) √32r Q.3 The numbers of tetrahedral voids in the unit cell of a face centered cubic lattice of

similar atoms is- (A) 4 (B) 6

(C8 (D)10

Q.4 The percentage of empty space in a body centred cubic arrangement is – (A) 74 (B)68

(C) 32 (D) 26

Q.5 The number of atoms in unit cell in simple cubic, FCC and BCC are- (A) 1,2,4 (B) 1,2,3

(C) 1,4,2 (D) 1,3,2

11

SECTION-B

CASE STUDY BASED-ASSERTION REASON TYPE QUESTIONS


In the formation of crystals, the constituent particles (atoms, ions or molecules) get closely packed together. The closely packed arrangement is that in which maximum available space is

occupied. This corresponds to a state of maximum density. The most efficient close packing can be achieved in two ways, one which is called hexagonal close packing (hcp) and the other cubic

close packing (ccp or fcc).

In the following questions, a statement of assertion is followed by a statement of reason.

Mark the correct choice as

(A) Assertion and reason both are correct statements and reason is correct explanation for

assertion.

(B) Assertion and reason both are correct statements but reason is not correct explanation for

assertion.

(C) Assertion is correct statement but reason is wrong statement.

(D) Assertion is wrong statement but reason is correct statement.

Q.1 Assertion:The packing efficiency is maximum for the fcc structure.

Reason:The coordination number is 12 in fcc structures.

Q.2 Assertion:In close packing of spheres, a tetrahedral void is surrounded by four

spheres whereas an octahedral void is surrounded by six spheres.

Reason: A tetrahedral void has a tetrahedral shape whereas an octahedral

void hasan octahedral shape.

Q. 3 Assertion:Packing fraction of FCC and HCP unit cells are the same. Reason: Both FCC and HCP unit cells have same packaging pattern i.e.ABCBC..

Q.4 Assertion:The octahedral viods have double the size of the tetrahedral voids in a crystal.

Reason: The number of tetrahedral voids is double the number of octahedral

voids is a crystal

Q.5 Assertion:hcp is more closely packed than bcc.

Reason:hcp has 12 coordination number and bcc has 8 coordination number.

2.Read the passage given below and answer the following questions: Non-Stoichiometric Defect

The defect in which the ratio of cation and anion in an ionic lattice is variable is known as a non-

stoichiometric defect. They are of two types, namely:

Metal Excess Defect

Metal Deficiency Defect

Metal Excess Defect occurs in two ways:

(a)Due to anionic vacancies (b) Due to presence of extra cations at interstitial sites

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Impurity defects are foreign atoms that replace some of the atoms making up the solid or that

squeeze into the interstices; they are important in the electrical behaviour of semiconductors,

which are materials used in computer chips and other electronic devices.

In the following questions a statement of assertion followed by a statement of reason

is given. Choose the correct answer out of the following choices.


assertion.

(B Assertion and reason both are correct statements but reason is not correct explanation for

assertion.



Q.1 Assertion:Anionic vacancies in alkali halides are produced by heating the alkali

halide crystals with alkali metal vapour.

Reason:Electrons trapped in anion vacancies are referred to as F−centre.

Q.2 Assertion:ZnO becomes yellow when it is heated.

Reason:Metal excess defect arises due to excess of Zn2+ ions which move to

interstitial sites and the electron moves to neighbouring interstitial

sites.

Q.3 Assertion:when impurity defect arises by adding SrCl2 in NaCl, it increases density

Reason:cationic vacancies are created.

Q.4 Assertion:Metal deficiency defect can be seen in FeO

Reason:Li compound (LiCl) shows pink colour when heated with Li vapour due to

F- center. Q.5 Assertion:Feo is non stochiometric with Fe0.95O

Reason:some Fe2+ ions are replaced by Fe3+ as 3 Fe2+=2 Fe3+ to maintain electrical

neutrality.

SECTION-C

ASSSERTION REASONING TYPE QUESTIONS

Note: In the following questions a statement of assertion followed by a statement of

reason is given. Choose the correct answer out of the following choices.


assertion.

(B Assertion and reason both are correct statements but reason is not correct explanation for

assertion.



1. Assertion: Crystalline solids are anisotropic.

Reason:Crystalline solids are not as closely packed as ionic solids.

2.Assertion: Solid NaCl does not conduct electricity at all.

Reason: In solid NaCl, the ions have fixed positions in the lattice structure and there are

no free ions.

3. Assertion:Ionic compounds have high melting and boiling points.

Reason:There is a strong force of attraction between the ions.

13

4.Assertion:NaCl crystal appears yellow upon heating in Na vapours.

Reason:Na+ in the crystal absorbs electrons from the air and hence gives yellow colour.

5.Assertion:Frenkel defect is shown by silver halides.

Reason:Silver ions are smaller in size and can easily fit in interstitial sites.

6. Assertion:In close packing of spheres,a tetrahedral void has a tetrahedral shape.

Reason: A tetrahedral void is surrounded by four spheres.

7. Assertion:The total number of atoms present in a simple cubic unit cell is one.

Reason:Simple cubic unit cell has atoms at its corners, each of which is shared

between eight adjacent unit cells.

8. Assertion:Graphite is an example of tetragonal crystal system.

Reason: For a tetragonal system, a = b ≠ c, α = β = 90°, γ = 120°.

9. Assertion:No compound has both Schottky and Frenkel defects.

Reason: Schottkeydefects change the density of the solid.

10. Assertion:Stability of a crystal is reflected in the magnitude of its melting.

Reason:The stability of a crystal depends upon the strength of the interparticle

attractive force.

SECTION-D

MULTIPLE CHOICE QUESTION

Q.1. Which of the following statements about amorphous solids is incorrect ?

(A) They melt over a range of temperature (B) They are anisotropic (C) There is no orderly arrangement of particles

(D) They are rigid and incompressible Q.2. Which of the following is not a characteristic property of solids?

(A) Intermolecular distances are short. (B) Intermolecular forces are weak. (C) Constituent particles have fixed positions.

(D) Solids oscillate about their mean positions. Q.3. Most crystals show good cleavage because their atoms, ions or molecules are

(A) weakly bonded together (B) strongly bonded together (C) spherically symmetrical

(D) arranged in planes Q.4. Which of the following is not a crystalline solid?

(A) KCl (B) CsCl (C) Glass

(D) Rhombic S Q.5. Which of the following is an amorphous solid ?

(A) Graphite (C)

(B) Quartz glass (SiO2)

(C) Diamond

(D) Silicon carbide (SiC)

14

Q.6. What type of crystal defect is shown in figure given below?

(A) Frenkel Defect

(B) Schottky Defect

(C) Interstitial Defect

(D) Impurity defect

Q.7. Graphite is an example of-

(A) Ionic solid (B) hydrogen bonded solid

(C) metallic crystal (D) Covalent solid Q.8. The intermetallic compound LiAg crystallizes in a cubic lattice in which lithium

and silver atoms have coordination numbers of 8. To what crystal class does the unit cell belong?

(A) Simple cubic (B) Face-centred cubic (C) Body-centred cubic

(D) Edge-centred cubic

Q.9. The arranegement ABC, ABC, ABC ……. is referred as-

(A) octahedral close packing (B) hexagonal close packing

(C) tetrahedral close packing (D) cubic close packing

Q.10.Cells present in a cube-shaped ideal crystal of NaCl of mass 1.00 g ?

[Atomic masses : Na = 23, Cl = 35.5]

(A) 2.57 × 1021 (B) 1.28 × 1021 (C) 1.71 × 1021

(D) 5.14 × 1021

Q.11. The packing efficiency of a metal crystal for simple cubic lattice is

(A) 52.4% (B) 65% (C) 60%

(D) 54.5%

Q.12. In compound atoms of element Y forms ccp lattice and those of element X occupy 2/3rd of

tetrahedral voids. What is the formula of the compound ? (A)X3Y4 (B) X4Y3

(C) X2Y4 (D) X2Y

Q.13. The total number of tetrahedral and octahedral voids in 0.5 mol of a compound forming hcp structure are: (A) 6.022 ×1023

(B) 3.01×1023 (C) 9.033 ×1023

(D) 12.044 ×1023

15

Q.14. A compound formed by elements A and B has cubic structure in which A atoms

are at the corners of the cube and B atoms are at the face centres. The formula of the compound will be__________. (A) AB3

(B) A2B (C) AB2

(D) A2B3 Q.15.Copper crystal has a face centred cubic structure. Atomic radius of copper atom is 128 pm. What is the density of copper metal? (Atomic mass of copper is 63.5)

(A) 10.71 g cm-3 (B) 4.93 g cm-3

(C) 8.9 g cm-3 (D) 11.2 g cm-3

Q.16. A crystal has the lattice parameters a ≠ b ≠ c and α ≠ β ≠ γ ≠ 900correspond to (A) monoclinic

(B) triclinic (C) cubic

(D) tetragonal Q.17. Analysis shows that nickel oxide has the formula Ni0.98O1.00. What fractions of nickel exist as Ni2+ and Ni3+ ions

(A) 96% and 4% (B) 92 % and 8%

(C) 88% and 12% (D) 99% and 1% Q.18. In a fcc arrangement of P and Q atoms, where P atoms are at the corners of

the unit cell, Q atoms at the face centres and two atoms are missing from two corners in each unit cell, then the formula of the compound is.

(A)P2Q3 (B) P4Q (C)P4Q5

(D)PQ4 Q.19. The cubic unit cell of Al (molar mass 27 g mol-1 ) has an edge length of 405 pm. Its

density is 2.7 g/cm3 . The cubic unit cell is _______. (A) face- centred (B) body- centred

(C) edge- centred (D) primitive

Q.20. How many kinds of space lattices are possible in a crystal ? (A) 7 (B) 14

(C) 23 (D) 230

Q.21. The correct order of the packing efficiency in different types of unit cells is (A) fcc < bcc < simple cubic (B) fcc > bcc > simple cubic

(C) fcc < bcc > simple cubic (D) bcc < fcc > simple cubic

Q.22. Which of the following point defects are shown by AgBr(s)crystals ? (i) Schottky defect

(ii) Frenkel defect (iii) metal excess defect

(iv) Metal deficiency defect

16

(A) (i) and (ii)

(B) (iii) and (iv) (C) (i)and (iii) (D) (ii) and (iv)

Q.23. The edge lengths of the unit cells in terms of the radius of spheres

constituting fcc, bccand simple cubic unit cell are respectively

(A) √

√

(B)

√ √

(C) √

√

(D)

√ √

Q.24.which of the following is a network solid? (A) SO2 (solid) (B) I2

(C) Diamond (D) H2O(ice)

Q.25.Aluminium crystallises in a cubic close-packed structure. Its metallic radius is 125 pm. What is the length of the side of the unit cell-

(A) 253.5pm (B) 453.5pm

(C) 335.5pm (D) 353.5pm

Q.26.The lattice site in a pure crystal cannot be occupied by____________ (A) molecule (B) ion

(C) electron (D) atom

Q.27. A compound MpXq has cubic close packing (ccp) arrangement of X. its unit cell structure is shown below:

The empirical formula of the compound is- (A) MX

(B) MX2

(C) M2X

(D) M5X14 Q.28.Gold crystallizes in fcclattice.Calculate the approximate number of unit cells Present in 1mg of Gold(At. Mass of gold=197u)

(A) 7.64× 10 17 (B) 3.82× 10 8

(C) ) 1.528× 10 17 (D) ) 6.022× 10 18

Q.29. An element has a body-centred cubic (bcc) structure with cell edge of 288 pm. The

density of the element is 7.2 g cm-3. How many atoms are present in 208 g of the element (A) 24.17× 10 24

(B) 2.417× 10 24 (C) 8.89× 10 23

(D) 8.89× 10 24 Q.30. The efficiency of packing is 68% in (A) hcp structure

(B) ccp structure (C) fcc structure

(D) bcc structure

17

Answer key: (I) Case study based (MCQ type )

1.

1 2 3 4 5

D D C A B

2.

1 2 3 4 5

D C D A D

3.

1 2 3 4 5

C B C C C

(II) Case study based (A/R) type )

1.

1 2 3 4 5

A A C D A

2.

1 2 3 4 5

B A B B A

(III) A/R Type questions:

1 2 3 4 5 6 7 8 9 10

C A A C A A A D D A

(IV) MCQ Type questions:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

B B D C B B D C D A A B C A C

16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

B A D A B B A A C D C B A B D

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2. SOLUTION

SECTION-A

CASE STUDY BASED-MULTIPLOE CHOICE QUESTIONS

1. Read the passage given below and answer the following questions: For chemical reactions the concentration of the solute is important because it determines the collision of molecules in solution for the reaction product. The rate of reaction depends upon the

collision of molecules and the equilibrium conditions. The concentration of a solution is the amount of solute present in a solution or dissolved in a fixed volume of solvent at room temperature. There are different terms to express the concentration of the solution like

percentage concentration, molarity, normality, formality, molality etc.

Answer the following questions by choosing the most appropriate answer: 1. The number of moles of solute present in a 1 litre of solution is known as-

(A) Molality (B) Molarity

(C) Normality

(D) Formality 2. If 2 gm of NaOH is present is 200 ml of its solution, its molarity will be

(A) 0.025 (B) 0.5

(C) 0.25

(D) 10 3. The correct relationship between mole fraction and molality is-

(A)

(B)

(C) m= X1+X2 (D) m= X/V

4. Calculate molality of the mixture of solution produced by mixing 25 % (W/W) of NaOH solution with 15 % w/w solution? (Molar mass of NaOH = 40 g/mol) (A) 12.74m

(B) 5.5m (C) 9.0m

(D) 4.0m

5. Calculate concentration of urea having 6.022x1020 molecules in 100 ml Urea (NH2CONH2)

solution? (A) 0.01M

(B) 0.001M (C) 0.2M (D) 0.1M

2. Read the passage given below and answer the following questions: The properties of the solutions which depend only on the number of solute particles but not on the nature of the solute are called colligative properties. Relative lowering in vapour pressure is

also an example of colligative properties. For an experiment, sugar solution is prepared for which lowering in vapour pressure was found to be 0.061 mm of Hg. (Vapour pressure of water at 200C is 17.5 mm of Hg)

19

The following questions are multiple choice questions. Choose the most

appropriate answer: 6. Relative lowering of vapour pressure for the given solution is

(A) 0.00348 (B) 0.061

(C) 0.122 (D) 1.75

7. The vapour pressure (mm of Hg) of solution will be

(A) 17.5 (B) 0.61

(C) 17.439 (D) 0.00348 8. Mole fraction of sugar in the solution is

(A) 0.00348 (B) 0.9965

(C) 0.061 (D) 1.75

9. If weight of sugar taken is 5 g in 108 g of water then molar mass of sugar will be

(A) 358 (B) 120

(C) 240 (D) 400

10. The vapour pressure of water at 293K when 25g of glucose is dissolved in 450 g of water

is (A) 17.2

(B) 17.4 (C) 17.120 (D) 17.02

3. Read the passage given below and answer the following questions: An everyday example of Henry's law is given by carbonated soft drinks. Before the bottle or can

is opened, the gas above the drink is almost pure carbon dioxide at a pressure slightly higher than atmospheric pressure.When soft drinks bottle is opened some of the gas escapes giving a

specific pop sound, this is due to the lower pressure above the liquid and carbon dioxide comes out as bubbles. Carbon dioxide reacts with water, the electron rich oxygen of water donates an electron pair to the carbon. After proton transfer from water to one oxygen of the CO2unit,

carbonic acid is formed. Henry's law states that the solubility of a gas in a liquid is directly proportional to the

pressure of the gas on liquid. Henry's law is a gas law which states that at the amount of gas that is dissolved in a liquid is directly proportional to the partial pressure of that gas above the liquid when the temperature is kept constant.

The Henry law constant for dissolution of a gas in an aqueous medium is 3×102 atm.We can use Henry's Law to calculate the concentration of dissolved carbon dioxide in an aqueous

solution. The current average concentration of CO2 is 387 ppm, that is 387 x 10-6 atm. [CO2] = P/KH = 3.87 x 10-4 atm/29.41 atm M-1 = 1.32 x 10-5 M


appropriate answer: 11. Henry‘s law states that -

(A) Partial pressure of a component over a solution is proportional to its mole

fraction in the liquid

(B) Partial pressure of a component over a solution is proportional to the mole

Fraction in the vapour

(C) Partial pressure is equal to the product of the mole fraction and total pressure

(D) Vapour pressure is equal to the product of the mole fraction and total pressure

20

12. On increasing pressure of a gas, solubility of gas in liquid: (A) Decreases

(B) Increases (C) First Increases then decreases (D)None

13. The value of the Henry‘s law constant of a gas is dependent on (A) Nature of gas

(B) Nature of solvent (C) Temperature (D) All of these

14. Calculate the solubility of gaseous oxygen in water at a temperature of 293 K when the

partial pressure exerted by O2 is 1 bar. (Given: kH of O2 34840 barLmol-1)

(A) 2.87x10-5 M (B) 1.80x10-5 M (C) 3.07x10-5 M

(D) 2.87x10-2 M 15. The value of kH for CO2 at a temperature of 293 K is 1.6x103 atm.L.mol-1. At what partial

pressure would the gas have solubility (in water) of 2x10-5 M? (A) 2.032 atm (B) 1.02 atm

(C) 0.032 atm (D) 0.57 atm

SECTION-B

CASE STUDY BASED-ASSERTION REASON TYPE QUESTIONS

4. Read the passage given below and answer the following questions

Osmotic pressure is defined as the tendency of solvent molecules to move in the direction of

lower solvent activity through semipermeable membrane. Osmotic pressure is considered to be proportional to the molarity and temperature of the solution. By molarity we mean the number

of moles of solute in one liter solution, therefore it is a colligative property. Osmotic pressure can be defined using the following equation: Π V = nRT

An external pressure must be applied to reverse the process of osmosis on the side of the membrane that contains the lower solvent concentration. The pressure forces the solvent to flow

from a region of low concentration to one of high concentration. This concept is used in desalination of sea water.

In following questions a statement of assertion followed by a statement of

reason is given. Select the correct answer out of the following choices.

(A) Assertion and reason both are correct statements and reason

is correct explanation for assertion.

(B) Assertion and reason both are correct statements but reason

is not correct explanation for assertion.



16. Assertion: When a solution is separated from the pure solvent by a semi

permeable membrane, the solvent molecules pass through it

from pure solvent side to the solution side. Reason: Diffusion of solvent occurs from a region of high concentration solution to a region of low concentration solution.

21

17. Assertion: Isotonic solution does not show net osmosis.

Reason: Isotonic solutions have same osmotic pressure.

18. Assertion: Osmotic pressure of 0.1 M urea solution is less than that of 0.1M NaCl solution.

Reason: Osmotic pressure is not a colligative property.

19. Assertion: The preservation of meat by salting and fruits by adding sugar

protects against bacterial action.

Reason: A bacterium on salted meat loses water due to osmosis shrivels and

ultimately dies.

20. Assertion: Water purifiers works on reverse osmosis.

Reason: Movement of solvent from a region of high concentration solution

to a region of low concentration solution is reverse osmosis.

5. Read the passage given below and answer the following questions :

At the freezing point of a solvent, the solid and the liquid are in equilibrium. Therefore, a

solution will freeze when its vapour pressure becomes equal to the vapour pressure of the

pure solid solvent.

It has been observed that when a non-volatile solute is added to a solvent, the freezing point

of the solution always lower than that of the pure solvent. Depression in freezing point can be

given as, ∆Tf= Kf m Where, Kf =Molal freezing point depression constant or

In following questions a statement of assertion followed by a statement of reason is

given. Select the correct answer out of the following choices.

(A) Assertion and reason both are correct statements and reason is

correct explanation for assertion.

(B) Assertion and reason both are correct statements but reason is not

correct explanation for assertion.



21. Assertion: 0.1 M solution of glucose has same depression in the freezing point

As 0.1 M solution of urea.

Reason: Kf for both has same value.

22. Assertion: Larger the value of cryoscopic constant of the solvent, lesser will be

the freezing of the solution.

Reason: Extent of depression in the freezing-point depends on the nature of the solvent.

23. Assertion: The water pouch of instant cold pack for treating athletic injuries

Breaks when squeezed with NH4N03 . Reason: Addition of non-volatile solute into solvent results into depression of

Freezing point of solvent. 24. Assertion: If a non-volatile solute is mixed in a solution then elevation in

Boiling point and depression in freezing point both will be same.

Reason: Elevation in boiling point and depression in freezing point both

Depend on number of particles of solute. 25. Assertion: Increasing pressure on pure water decreases its freezing point.

Reason: Density of water is maximum at 273 K.

en

io

22

SECTION-C


Directions: These questions consist of two statements, each printed as Assertion and

Reason. While answering these questions, you are required to choose any one of the following four responses.

(A) If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion. (B) If both Assertion and Reason are correct but Reason is not a correct explanation of

the Assertion. (C) If the Assertion is correct but Reason is incorrect.

(D) If both the Assertion and Reason are incorrect.

26. Assertion: When molecular mass of Acetic acid in Benzene and in water is

calculated using depression in freezing point it gives different

values. Reason: Water is polar and benzene is non polar solvent.

27. Assertion: In liquid state molarity changes with change in temperature.

Reason: Volume changes with change in temperature. 28. Assertion: Molarity of the solution does not change on dilution.

Reason: Ratio of moles of solute to the volume of solution is called molarity.

29. Assertion: Ideal solution is prepared by mixing benzene and toluene.

Reason: On mixing 25 ml benzene with 25ml toluene, the volume of solution become 50 ml and there is no change in the enthalpy of mixing.

30. Assertion: 1 molal aqueous solution of urea contains 60 gm urea in 1Kg water.

Reason: 1 mole solute dissolved in 1000gm solvent the resultant solution is called a 1 Molal solution.

31. Assertion: 0.9% (w/w) solution of NaCl is isotonic with blood cells.

Reason: isotonic solutions have equal osmotic pressure. 32. Assertion: Osmotic pressure of 0.1 M urea solution is greater than that of

0.1M NaCl solution.

Reason: Osmocis is a colligative property. 33. Assertion: To remove snow from road, salt is used.

Reason: NaCl decrease freezing point of water.

34. Assertion: Pressure cooker decreases time of cooking food.

Reason: Boiling point of water decrease in pressure cooker. 35. Assertion: The boiling point of water is higher than H2S.

Reason: H2S has a greater molecular mass than H2O.

Multiple choice Questions- 36. According to Raoult‘s law relative lowering in vapour pressure of non-volatile solute is

equally proportional to-

(A) mole fraction of solvent (B) mole fraction of solute

(C) mass fraction of solute (D) mass fraction of solution

37. If 200 ml water is added to 0.2 M 500 ml solution calculate molarity (M) of diluted

solution?

(A) 0.5010 M (B) 0.2847 M

(C) 0.7093 M (D) 0.1428 M

23

38. A 1% aqueous solution (w/w)of a certain substance is isotonic with a 3%solution of

dextrose i.e., glucose (M.M. 180 g/mol) at a temperature. The molar mass in g/mol of the substance is: (A) 60

(B)120 (C)180

(D) 360 39.Which of the following pair will show positive deviation from Raoult‘s law?

(A) H2O- HCl

(B) C6H6- CH3OH (C) H2O- HNO3

(D) CH3COCH3- CHCl3 40.Which of the following solutions has highest osmotic pressure?

(A) 1 M NaCl (B) 1 M Urea (C) 1 M Sucrose

(D) 1M Glucose 41.Which of the following behaviour is true about ideal binary liquid solution?

(A) Plot of pTotal vs xA is non-linear (B) Plot of pTotal vs xB is linear (C) Plot of pT vs xB is linear with slope=0

(D) Plot of pT vs xA is linear with slope=0 42.The relative lowering of vapour pressure in case of a solution of non- volatile solute is

equal to the mole fraction of solute. The statement is based on- (A)Henry‘s law

(B) Arrhenius law

(C) Raoult‘s law (D) Ostwald‘s law

43.Which pair will not form ideal solution- (A) C2H5Br, C2H5I (B) C6H5Br,C6H5Cl

(C) C6H6,C6H5CH3 (D)C2H5I, C2H5OH

44. Which of the following aqueous solution has highest boiling point? (A) 1% glucose (B) 1% sucrose

(C) 1% NaCl (D) 1% CaCl2

45.Osmotic pressure of the solution can be increased by (A) Increasing temperature of the solution

(B)decreasing temperature of the solution

(C) Increasing the volume of the solution (D) diluting the solution

46.The van‘t Hoff‘s factor for 0.1 M Ba(NO3)2 solution is 2.74. The degree of dissociation is (A) 91.3% (B) 87%

(C) 100% (D) 74%

47.A pressure cooker reduces cooking time for food because (A) heat is more evenly distributed in cooking space

(B) boiling point of water involved in cooking is increased (C) higher pressure inside the cooker cruses food material (D) cooking involves chemical changes helped by rise in temperature

48.If liquid A and B form ideal solutions (A) The enthalpy of mixing is zero

24

(B) The entropy of mixing is zero

(C) The free energy of mixing is zero (D)the free energy as well as entropy of mixing are zero

49. On dissolving definite amount having molecular mass 60 gm/mole of substance in 180

gm of water, the vapour pressure of water decreases by 10% then calculate the amount dissolved ?

(A) 30 gm (B) 120 gm (C) 12 gm

(D) 60 gm 50.Calculate molarity of the solution produced by dissolving 120 gm urea. (molecular mass

60u) in1000 gm of water having density 1.15 gm ? (A) 0.50 M

(B) 1.78 M (C) 1.02 M (D) 2.05 M

51.Which of the following has molar concentration same as 2N HCl? (A) 4.0 N H2SO4

(B) 0.5 N H2SO4

(C) 1 N H2SO4

(D) 2 N H2SO4

52.Vapour pressure of CCl4at 25°C is 143 mm. If 0.5 gm non volatile solute is added in 100 cm3 of CCl4 calculate vapour pressure of the solution (density of CCl4= 1.58 gm/cm3)

(A) 141.93 mm (B) 94. 39 mm (C) 199.34 mm

(D) 143.99 mm 53.If ratio of partial pressure of substance A and B is PA0: PB0=1 : 2 and ratio of mole

fraction is 1:2,then calculate molefraction of A in vapour state ? (A) 0.33 (B) 0.25

(C) 0.52 (D) 0.2

54.Vapour pressure of a mixture of ethanol and propanol at 300 K is 290 mm. If vapour pressure of propanol at 300 K is 200 mm and mole fraction of ethanol is 0.6 then at the same temperature calculate vapour pressure of ethanol?

(A) 300 mm (B) 700 mm

(C) 350 mm (D) 360 mm

55.At a definite temperature vapour pressure of pure benzene is 0.85 bar. When 0.5 gm of

solid non-volatile electrolyte is dissolved in 39.0 gm benzene vapour pressure of solution becomes0.845 bar calculate molecular mass of the solid substance ?

(A) 58 gm mole–1

(B) 170 gm mole–1

(C) 180 gm mole–1

(D) 135 gm mole 56. Solution of Acetone in ethanol ..........

(A) shows positive deviation from Raoult‘s law (B) acts as an Ideal solution

(C) Obeys Raoult‘s law (D) shows negative deviation from Raoult‘s law.

25

57. Which of the following pair will make an ideal solution ? (A) Chlorobenzene + Chloroethane

(B) Benzene + Toluene

(C) Acetene + Chloroform (D) water + HCl

58.Calculate molarity of 98%by mass H2SO4 at308K temperature having density1.84 gm/ml?

(A) 18.4 M

(B) 4.18 M (C) 8.14 M

(D) 1.8 M 59.Calculate mole fraction of amount of solute dissolved in 1.00 molal (m) of Aqueous

solution ? (A) 0.1770

(B) 0.0177

(C) 0.0344 (D) 1.7700

60.Calculate concentration of nitrate ions in the mixture of solution produced by mixing 2 litre 3M AgNO3 solution with 3 litre 1 M BaCl2 solution ?

(A) 1.2 M

(B) 1.8 M (C) 0.5 M

(D) None of the above 61.How much water should be added to have 3M molarity of a mixture of solution produced

by mixing250 ml of 6M HCl solution with 650 ml. of 3M HCl solution?

(A) 250 ml (B) 1150 ml

(C) 500 ml (D) 575 ml

62.Molal elevation constant of water in 1.2 m glucose solution is 0.52 KKgmol-1. What will be

its value in 0.18 m glucose solution? (A) 0.52 KKgmol-1

(B) 0.26 KKgmol-1l (C) 1.04 KKgmol-1 (D) None of the above

63.Calculate formality of solution produced by dissolving 5.85 gm NaCl in water to make 0.5L solution?

(A) 0.2 M (B) 0.4 M (C) 1.0 M

(D) 0.1 M 64.To make a decimolar solution in 100 ml how many grams of a dibasic acid having

molecular mass200 gm/mole should be added? (A) 20 gm

(B) 1 gm

(C) 2 gm (D) 10 gm

65. The osmotic pressure is expressed in the units of-

(A) MeV (B)Calories

(C)atmosphere (D) cm/sec

26

ANSWER KEY-

1 2 3 4 5 6 7 8 9 10

B A B B A A C A C B

11 12 13 14 15 16 17 18 19 20

A B D A C B B C A A

21 22 23 24 25 26 27 28 29 30

B A D D C A A D A A

31 32 33 34 35 36 37 38 39 40

B D A C B B D A B A

41 42 43 44 45 46 47 48 49 50

B C D D B B B A D D

51 52 53 54 55 56 57 58 59 60

A A D C B A B A B D

61 62 63 64 65

A A A C C

27

3. p- BLCOK ELEMENTS

SECTION-A

CASE STUDY BASED-MULTIPLOE CHOICE QUESTIONS (I)

All the elements of Group 15 form hydrides of the type EH3 where E = N, P, As, Sb or Bi. The

hydrides show regular gradation in their properties. The stability of hydrides decreases from NH3

to BiH3 which can be observed from their bond dissociation enthalpy. Due to high

electronegativity and small size of nitrogen, NH3 exhibits hydrogen bonding in solid as well as

liquid state. All these elements form two types of oxides: E2O3 and E2O5. The oxide in the higher

oxidation state of the element is more acidic than that of lower oxidation state.

Answer the following questions

1. The correct increasing order of thermal stability of hydrides of 16th group is

(a) H2O <H2S <H2Se <H2Te <H2Po

(b) H2Po <H2Te <H2Se < H2S <H2O

(c) H2S <H2Se <H2Te <H2Po <H2O

(d) H2S <H2Se <H2O <H2Po <H2Te

2. The correct order of basic strength of hydrides of group 15 elements

(a) BiH3< SbH3< AsH3< PH3< NH3

(b) BiH3> SbH3< AsH3> PH3< NH3

(c) BiH3> SbH3> AsH3> PH3> NH3

(d) BiH3< SbH3> AsH3> PH3< NH3

3. The strongest reducing agent amongst all the Hydrides of Group-15 elements.

(a) NH3 (b)PH3 c) BiH3 (d)AsH3

4. The acidic character of group 15 elements oxides

(a) decreased down the group

(b) increases down the group

(c) first decrease after Arsenic increases

(d) first increases then decreases after Arsenic

5. SO3 is more acidic than SO2, because:

(a) Oxidation state of Sulphur is higher in SO3

(b) SO3 is polar but SO2 is non polar

(c) SO3 is non polar but SO2 is polar

(d) All the S-O bonds in SO3 are non-identical

28

CASE STUDY BASED-MULTIPLOE CHOICE QUESTIONS (II)

All the halogens exhibit –1 oxidation state. However, chlorine, bromine and iodine exhibit + 1, +

3, + 5 and + 7 oxidation states also. The higher oxidation states of chlorine, bromine and iodine

are realized mainly when the halogens are in combination with the small and highly

electronegative fluorine and oxygen atoms e.g., in inter halogens, oxides and Oxo acids. The

fluorine atom has no d orbitals in its valence shell and therefore cannot expand its octet. Being

the most electronegative, it exhibits only – 1 oxidation state.

1. Which of the following element is most reactive?

a) Chlorine b) Fluorine c) Bromine d) Iodine

2. Which of the following halogen is radioactive?

a) Fluorine b) Bromine c) Astatine d) Chlorine

3. What is the correct order of enthalpy of dissociation of halogens?

a) F2 > Cl2 > Br2 > I2 b) Cl2> Br2> F2> I2

c) Cl2> F2> Br2> I2 d) F2> Br2> Cl2> I2

4. Which of the following is true about interhalogen compounds?

a) They have unpaired electrons b) They are highly stable

c) They are diamagnetic d) They are paramagnetic

5. Which is the correct statement regarding halogens?

a) They are not all diatomic and form univalent ions

b) They are all diatomic and do not form univalent ions

c) They are all diatomic and form univalent ions

d) They are all diatomic and form bivalent ions

CASE STUDY BASED-MULTIPLOE CHOICE QUESTIONS (III)

Sulphuric acid is a colourless, dense, oily liquid with a specific gravity of 1.84 at 298 K. The acid

freezes at 283 K and boils at 611 K. It dissolves in water with the evolution of a large quantity of

heat. Hence, care must be taken while preparing sulphuric acid solution from concentrated

sulphuric acid. The concentrated acid must be added slowly into water with constant stirring.

The acid forms two series of salts: normal sulphates and acid sulphates. Sulphuric acid, because

of its low volatility can be used to manufacture more volatile acids from their corresponding

salts.

29

1. What is the first step involved in forming sulphuric acid through contact process?

a) Conversion of SO2 to SO3

b) Burning of Sulphur or roasting sulphide ores to generate SO2

c) Absorption of SO3 in sulphuric acid

d) Purifying SO3

2. What is the catalyst used in contact process in the conversion of Sulphur dioxide to Sulphur

trioxide?

a) Finely divided iron b) Molybdenum

c) Vanadium pentoxide d) Platinum

3. Which of the following is not a property of sulphuric acid?

a) It acts as a strong dehydrating agent b) It is a Lewis acid

c) It cannot char carbohydrates d) It is dense and oily

4. Which process is used for large scale manufacturing of sulphuric acid?

a) Haber‘s process b) Ostwald‘s process

c) Smith‘s process d) Contact process

5. Which of the following is true about sulphuric acid?

a) It is a soapy liquid b) It is a monobasic acid

c) It is a dibasic acid d) It is a tribasic acid

SECTION-B

CASE STUDY BASED-ASSERTION REASON TYPE QUESTIONS (I)

Oxygen and Sulphur are non-metals, selenium and tellurium metalloids, whereas polonium is a

metal. Polonium is radioactive and is short lived (Half-life 13.8 days). All these elements exhibit

allotropy. The melting and boiling points increase with an increase in atomic number down the

group The anomalous behaviour of oxygen, like other members of p-block present in second

period is due to its small size and high electronegativity Elements of Group 16 form a large

number of halides of the type, EX6, EX4 and EX

In the following questions a statement of assertion followed by a statement of reason is given.

Choose the correct answer out of the following choices.

(a) Both assertion and reason are correct statements, and reason is the correct explanation of

the assertion.

(b) Both assertion and reason are correct statements, but reason is not the correct explanation

of the assertion.

(c) Assertion is correct, but reason is wrong statement.

(d) Assertion is wrong but reason is correct statement.

(e) Both assertion and reason are wrong statements.

30

(1). Assertion: HI cannot be prepared by the reaction of KI with concentrated H2SO4

Reason: HI has lowest H–X bond strength among halogen acids.

(2) Assertion: Both rhombic and monoclinic Sulphur exist as S8 but oxygen exists as O2.

Reason: Oxygen forms pπ – pπ multiple bonds due to small size and small bond length but

pπ – pπ bonding is not possible in Sulphur.

(3) Assertion: SF6 cannot be hydrolyzed but SF4 can be.

Reason: Six F atoms in SF6 prevent the attack of H2O on Sulphur atom of SF6.

(4) Assertion:NaCl reacts with concentrated H2SO4 to give colourless fumes with pungent smell.

But on adding MnO2 the fumes become greenish yellow.

Reason: MnO2 oxidizes HCl to chlorine gas which is greenish yellow

(5). Assertion: Reaction of SO2 and H2S in the presence of Fe2O3 catalyst gives elemental

Sulphur.

Reason: SO2 is a reducing agent.

CASE STUDY BASED-ASSERTION REASON TYPE QUESTIONS (II)

Group 15 includes nitrogen, phosphorus, arsenic, antimony and bismuth. As we go down the

group, there is a shift from non-metallic to metallic through metalloid character. Nitrogen and

phosphorus are non-metals, arsenic and antimony metalloids and bismuth is a typical metal.

Covalent and ionic (in a particular state) radii increase in size down the group. There is a

considerable increase in covalent radius from N to P. However, from As to Bi only a small

increase in covalent radius is observed. This is due to the presence of completely filled d and/or

f orbitals in heavier members

In the following questions a statement of assertion followed by a statement of reason is given.



the assertion.


of the assertion.




(1). Assertion: Nitrogen does not form pentahalides

Reason: Nitrogen has no d-orbital.

(2) Assertion: The stability of +5 oxidation state increases due to inert pair effect.

Reason: Due to poor shielding effect of fully filled, d and f-orbitals, the ns2 electrons of the

heavier elements of p-block become passive towards bonding

31

(3) Assertion: Dinitrogen inert at room temperature

Reason: Dinitrogen is in gaseous state

(4). Assertion: pentahalides of Group-15 elements, more covalent than their trihalides

Reason: In +5 oxidation state, elements have more polarizing power than in +3 oxidation

state, so the covalent character of bond is more in pentahalides.

(5). Assertion: Reducing property of hydrides of group -15 elements increases down the group.

Reason: Down the group, the size of element increases and so the length of E----H bond

increases.

SECTION-C


In the following questions 1 TO 10 a statement of assertion followed by a statement of reason is

given. Choose the correct answer out of the following choices.


the assertion.


of the assertion.




1. Assertion :- H2S is less acidic than H2Te

Reason:- Due to decrease in E---H bond dissociation enthalpy, down the group, acidic

character increases

2. Assertion :- O3 act as a powerful oxidizing agent

Reason:- It decomposes to give O2 and nascent Oxygen.

3. Assertion :- O2 diamagnetic in nature

Reason:- It is because it has 2 unpaired electrons in its anti-bonding molecular orbitals.

4. Assertion :- S2 shows paramagnetic behavior.

Reason:- It is because it has 2 unpaired electrons in its anti-bonding molecular orbital.

5. Assertion :- HF is liquid and HCl is a gas

Reason:- due to the presence of Hydrogen bond in HF.

6. Assertion:- Helium is used in scuba divers apparatus

Reason:-Helium is less soluble in blood/ has very low solubility in blood.

7. Assertion:- PH3 has higher boiling point than NH3

32

Reason:- PH3 cannot form Hydrogen bond.

8. Assertion:- The stability of -3 oxidation state, decreases down the group for group 15.

Reason:- It is due to increase in size and metallic character or decrease in electronegativity

down the group

9. Assertion:- XeF2 has linear geometry

Reason:- The molecule has two lone pair of electron.

10. Assertion:- Noble gases have very low boiling points

Reason:- Noble gases being monoatomic have no interatomic forces except weak dispersion

forces.

SECTION-D

MULTIPLE CHOICE QUESTION

1. Which of the following represents the general electronic configuration of an element

belonging to the p-block of the periodic table?

a)(n-2)f0(n-1)d0ns2 np0-6 b) (n-2)f0(n-1)d1 – 10 ns2 np1- 6

c) (n-2)f0(n-1)d0 ns2np1-6 d) (n-2)f1- 14(n-1)d1- 10ns2np1- 6

2. What happens to the size of atoms of elements of p-block as we move from left to right

in the same period?

a)Size increases b) Size decreases

c) Size does not change d) Size increases then decreases

3. What is the maximum covalency of the nitrogen atom?

a) One b) Two c) Three d) Four

4. Why does nitrogen show poor tendency towards catenation?

a) N atom can form multiple pπ – pπ bonds

b) Octet of N2 is complete unlike carbon

c) The N ≡ N is unreactive at room temperature

d) The N – N single bond is weaker and unstable

5. What is the primary product of Haber-Bosch process?

a) Ammonia b) Nitric acid

c) Nitrous acid d) Pyridine

6. Which gas is released when copper chips are subjected to concentrated nitric acid?

a) Nitrogen (I) oxide b) Nitrogen (II) oxide

c) Nitrogen (III) oxide d) Nitrogen (IV) oxide

7. What catalyst is used for oxidation of ammonia to produce nitric acid

a) Palladium hydride b) Sodium amalgam

c) Platinum-Rhodium gauze d) Vanadium (V) oxide

33

8. What is the oxidation state of nitrogen in di-nitrogen trioxide?

a) +1 b) +2 c) +3 d) +4

9. Which of the following elements does not belong to group 16 of the periodic table?

a) Oxygen b) Phosphorus c) Sulphur d) Selenium

10. Which of the following statements regarding group 16 elements is not true?

a) The electronic configuration of Oxygen is [He]2s22p4

b) The electronic configuration of Sulphur is [Ne]3s23p4

c) The atomic radii of the elements of group 16 are larger than those of the corresponding

elements of group 15

d) The electronic configuration of Tellurium is [Kr]4d105s25p

11. Which group 16 element is the most electronegative?

a) Sulphur b) Polonium c) Oxygen d) Selenium

12. Which group 16 element has the highest tendency for catenation?

a) Oxygen b) Sulphur c) Selenium d) Polonium

13. What is the correct order of reactivity of group 16 elements?

a) O > Se > S >Te> Po

b) S > O >Te> Po > Se

c) S > O > Se >Te> Po

d) O > S > Se >Te> Po

14. What is the correct order of enthalpy of dissociation of halogens?

a) F2 > Cl2 > Br2 > I2 b) Cl2 >Br2 > F2 > I2

c) Cl2 > F2 > Br2 > I2 d) F2 > Br2 > Cl2 > I2

15. Which of the following halogen exists as a solid at room temperature?

a) Chlorine b) Fluorine c) Iodine d) Bromine

16. Which of the following noble gases do not occur in the elemental state in the

atmosphere?

a) Helium b) Neon c) Argon d) Radon

17. Which of the following is the second most abundant noble gas in the atmosphere?

a) Helium b) Argon c) Neon d) Krypton

18. Which of the following noble gases is not obtained via fractional distillation?

a) Krypton b) Argon c) Neon d) Helium

19. Which of the following statements is incorrect about noble gases?

a) They are monoatomic b) They are colourless

c) They are odourless d) They all have an outer electronic configuration of ns2np6

20. What is the electron gain enthalpy for noble gases?

a) > 0 b) < 0 c) = 0 d) It is not defined for noble gases

34

21. Which of the following statements are correct?

(a) Among halogens, radius ratio between iodine and fluorine is maximum.

(b) Except F – F bond, all halogens have weaker X – X bond than X – X‘ bond in inter-

halogens.

(C) Among inter-halogen compounds maximum number of atoms are present in iodine

fluoride.

(d) Inter-halogen compounds are more reactive than halogen compounds.

22. When XeF6 is partially hydrolysed by one mole of H2O, it yields

(a) XeSO3 (b) XeOF2 (c) XeOF4 (d) XeF2

23. Complete the following reaction: Xe + PtF6

(a) Xe + PtF6 XeF4 + PtF2 (b) Xe + PtF6 XeF6 + Pt

(c) Xe + PtF6Xe+[PtF6]– (d) Xe + PtF6 XeO2F4 + Pt

24. The shape of XeF4 is

(A) tetrahedral (B) square planar (C) pyramidal (D) linear

25. Which of the following statements are true?

(a) Only types of interactions between particles of noble gases are due to weak

dispersion forces.

(b) Hydrolysis of XeF6 is a redox reaction.

(c) Xenon fluorides are not reactive.

(d) None of the above

26. Which of the following statements is correct?

(a) S–S bond is present in H2S2O8.

(b) In per oxo mono sulphuric acid (H2SO5) Sulphur is in +6 oxidation state.

(c) Iron powder along with Al2O3 and K2O is used as a catalyst in the preparation

of NH3 by Haber‘s process.

(d) Change in enthalpy is positive for the preparation of SO3 by catalytic

oxidation of SO2.

27. A black compound of manganese reacts with a halogen acid to give greenish yellow

gas. When excess of this gas reacts with NH3 an unstable tri-halide is formed. In this

process the oxidation state of nitrogen changes from:

(a) – 3 to +3. (b) – 3 to 0. (C) – 3 to +5. (d) 0 to – 3.

28. Which of the following statements are correct for SO2 gas?

(a) It acts as bleaching agent in moist conditions.

(b) Its molecule has linear geometry.

(C) It can be prepared by the reaction of dilute H2SO4 with metal sulphide.

(d) All of the above

35

29. Which of the following statements is wrong?

(a) Single N–N bond is stronger than the single P–P bond.

(b) PH3 can act as a ligand in the formation of coordination compound with transition

elements.

(C) NO2 is paramagnetic in nature.

(d) Covalency of nitrogen in N2O5 is four.

30. Which of the following are per oxo acids of Sulphur?

(A) H2SO5 and H2S2O8

(B) H2SO5 and H2S2O7

(C) H2S2O7 and H2S2O8

(D)H2S2O6 and H2S2O7

31. In the preparation of compounds of Xe, Bartlett had taken O2+PtF6

– as a base

compound. This is because

(A) both O2 and Xe have same size.

(B) both O2 and Xe have same electron gain enthalpy.

(C) both O2 and Xe have same ionisation enthalpy.

(D) bothXe and O2 are gases.

32. Which one of the following does not exist?

(A) XeOF4 (B) NeF2 (C) XeF2 (D) XeF6

33. Affinity for hydrogen decreases in the group from fluorine to iodine. Which of the

halogen acids should have highest bond dissociation enthalpy?

(A) H-F (B) HCl (C) HBr (D) HI

34. Which of the following does not react with oxygen directly?

(A) Zn (B) Ti (C) Pt (D) Fe

35. Which of the compounds will act as strongest reducing agent?

(A) NH3 (B) PH3 (C) AsH3 (D) SbH3

36. Which of the following elements can be involved in p∏–d∏ bonding?

(A) Carbon (B) Nitrogen (C) Phosphorus (D) Boron

37. On heating with concentrated NaOH solution in an inert atmosphere of CO, white

phosphorus gives a gas. Which of the following statement is incorrect about the gas?

(A) It is highly poisonous and has smell like rotten fish.

(B) It‘s solution in water decomposes in the presence of light.

(C) It is more basic than NH3.

(D) It is less basic than NH3.

38. In the complex ion [AuXe4]2+, Xe acts as:

(A) central atom (B) ligand

(C) chelating agent (D) electrophile

36

39. Compounds of noble gases except _______ are known.

(A) Krypton (B) Radon (C) Helium (D) Xenon

40.Which of the following oxide is more acidic

(A) As2O3 (B) P2O5 (C) N2O5 (D) Sb2O5

41. What is the range of the oxidation states shown by nitrogen in its oxides?

a) +1 to +3 b) +2 to +4 c) +1 to +2 d) +1 to +5

42. Fluorine differs from rest of the halogens in some of its properties. This is due to

(a) its smaller size and high electronegativity.

(b) lack of d-orbitals.

(c) low bond dissociation energy.

(d) All of these.

43. The set with correct order of acidity is

(a) HClO< HClO2< HClO3< HClO4

(b) HClO4< HClO3< HClO2<HClO

(c) HClO< HClO4< HClO3< HClO2

(d) HClO4< HClO2< HClO3<HClO

44. Helium is preferred to be used in air balloons instead of hydrogen because it is

(a) Incombustible (b) lighter than hydrogen

(c) More abundant than hydrogen (d) non polarizable

45. Among the 15th group elements, as we move from nitrogen to bismuth, the Penta

valency becomes less pronounced and tri valency becomes more pronounced due to

(a) Nonmetallic character

(b) Inert pair effect

(c) High electronegativity

(d) Large ionization energy

37

ANSWER KEY

SECTION-A

Case study based question PART-I(MCQ)

(I)- b (ii) a (iii) c (iv) a (v) a

Case study based question PART -II(MCQ)

(I)- b (ii) C (iii) b (iv) c (v) c

Case study based question PART -III(MCQ)

(I)- b (ii) C (iii) c (iv) d (v) c

SECTION-B

Case study based question PART-I (assertion/reasoning)

(1)- b (2) a (3) a (4) a (5) c

Case study based question PART-II (assertion/reasoning)

(1)- a (2) d (3) b (4) a (5) a

SECTION-C

ASSERTION REASONIN TYPE QUESTIONS

1. a 2. a 3. d 4. a 5. a 6. a 7. d 8. a 9. c 10. a

SECTION-D

ANSWER KEY OF QUESTION NO – 1 TO 30

1. C 2. B 3. D 4. D 5 a 6. D 7. C

8. C 9. b 10. C 11. C 12. B 13. D 14. B 15.b 16. D

17. C 18. D 19. D 20. A 21. D

22. C 23. C 24. B 25. a 26. B 27. A 28 a

29. A 30. A 31. C 32. B 33. A 34. C 35. A

36. C 37. C 38. B 39. C 40. C 41. D 42. D

43. A 44. B 45. B

**************************************

38

4. HALOALKANESANDHALOARENES

[SECTION- A]

CASEBASEDMCQ - I

1. Read the passage given below and answer the following questions:

Haloarenes are less reactive than haloalkanes. The low reactivity of

haloarenes can be attributed to

(i) Resonance effect

(ii) Sp2hybridisation of C- X bond

(iii) Polarity of C-X bond

(iv) Instability of phenyl cation

(v) repulsion between the electron rich attacking nucleophiles and electron rich arenes.

Reactivity of haloarenes can be increased or decreased by the presence of certain groups

atcertain positions for example, nitro (-NO2) group at ortho or para positions increases

there activity of haloarenes towards nucleophilc substitution reactions.


appropriate answer: (i) Aryl halides are less reactive towards nucleophilic substitution reaction as compared to alkylhalides due to- (A) The formation of less stable carbonium ion

(B) Resonance stabilisation

(C) Larger carbon-halogen bond length (D) Inductive effect.

(ii) Which of the following group at para position increase the reactivity of aryl halides towards nucleophilic substitution?

(A) -CH3

(B)-OCH3

(C)-NH2

(D)-NO2

(iii) Which one of the following will react fastest with aqueous NaOH?

A) Chlorobenzene B) BenzylChloride C) Cyclohexylchloride

D) All three react at equal rate (iv) The reactivity of the following compounds towards nucleophilic substitution

(i) CH3Br,(ii) CH3I,(iii) CH3Cl,(iv) CH3F decreases as

(A)(i)>(ii)>(iii)>(iv) (B)(iv)>(ii)>(i)>(iii) (C)(iv)>(iii)>(i)> (ii) (D)(ii)>(i)>(iii)>(iv)

(v) Increasing order of rate of nucleophilic reaction of following compounds is-

(A)(c)<(b)<(a) (B)(b)<(c)<(a) (C)(a)<(c)<(b) (D)(a) <(b) <(c)

39

CASEBASEDMCQ - II

2. Nucleophilic substitution reactions are of two types; substitution nucleophilic

bimolecular(SN2) and substitution nucleophilic unimolecular (SN1) depending on molecules taking part indetermining the rate of reaction. Reactivity of alkyl halide towards SN1 and SN2

reactions depends on various factors such as steric hindrance, stability of intermediate or transition state and polarity of solvent. SN2 reaction mechanism is favoured mostly by primary alkyl halide or transition state and polarity of solvent, SN2 reaction mechanism is

favoured mostly by primary alkyl halide then secondary and then tertiary. This order is reversed in case of SN1reactions.

The following questions are multiple choice question. Choose the most

appropriate answer: (i) Which of the following is most reactive towards nucleophilic substitution reaction? (A) C6H5Cl (B) CH2=CHCl

(C) ClCH2CH=CH2

(D) CH3CH=CHCl (ii) Isopropyl chloride undergoes hydrolysis by (A) SN1 mechanism (B) SN2 mechanism (C) SN1 and SN2 mechanism

(D) Neither SN1 nor SN2 mechanism

(iii) The most reactive nucleophile among the following is- (A) CH3O

-

(B) C6H5O-

(C) (CH3)2CHO-

(D) (CH3)3CO-

(iv) Tertiary alkyl halides are practically inert to substitution by SN2 mechanism because of- (A) insolubility

(B) instability

(C) inductive effect (D) steric hindrance

(v) Which of the following is the correct order of decreasing SN2 reactivity? (A) RCH2X>R2CHX>R3CX

(B) R3CX>R2CHX>RCH2X (C) R2CHX>R3CX>RCH2X

(D)RCH2X>R3CX>R2CHX


In Haloalkanes C-X bond is polar bond due to–I effect of halogen atoms so

haloalkanes more reactive than corresponding hydrocarbons. When a stronger nucleophile approaches the positively charged carbon atom of an alkyl halide, the

halogen atom alongwith its bonding electron pair gets displaced and a new bond with the carbon and the nucleophile is formed.These reactions are called nucleophilic

substitution reactions.

In these reactions the atom or group of atoms which loses its bond from carbon and takes on an additional pair of electrons is called leaving group.Halide ions are good

leaving groups..

40

i) Which of the following can not act as nucleophile ?

A) CO2 B) CH3NH2 C) NH3

D) H2O ii) What is the product if KCN act as a nucleophile?

A) Nitriles

B) Alkylisocyanide

C) both

D) none of the above

iii) The nucleophilic substitution of vinylchloride is difficult than ethyl chloride.Because

A) Vinyl group is electron withdrawing group

B) Vinyl group is electron releasing group

C) Vinyl Halide is resonance stabilised

D) Vinyl group does not have nucleophilic centre.

iv) Which of the following is more reactive towards nucleophilic substitution

A) CH3CH2Cl B) CH3CH2Br

C) CH3CH2I D) CH3CH2F

v) Aryl halides are less reactive than alkyl halides towards nucleophilic substitution. Which one of the following is not a correct reason?

(A) Resonance effect (B) sp2 hybridisation of C- Xbond (C) less polar of C- X bond (D) Stability of phenyl cation

[SECTION -B] :CASE BASED A/R QUESTIONS-I

1. Read the passage given below and answer the following questions: The order of reactivity towards SN1 reaction depends upon the stability of carbocation in

the first step.Greater the stability of the carbocation,greater will be its ease of formation from alkyl halide and hence faster will be the rate of the reaction. As we know, 3°

carbocation is most stable, therefore, the tert-alkyl that halides will undergo SN1 reaction very fast. For example, it has been observed that the reaction (CH3)3CBr with OH- ion to

give 2-methyl-2-propanol is about 1 million times as fast as the corresponding reaction of the methyl bromide to give methanol. The primary alkyl halides always react predominantly by SN2 mechanism. On the other

hand,the tertiary alkyl halides react predominantly by SN1 mechanism. Secondary alkyl halides may react by either mechanism or by both the mechanisms without much preference

depending up on the nature of the nucleophile and solvent. In these questions( i-v),a statement of assertion followed by a statement of reason is given.

Choose the correct answer out of the following choices. (A) Assertion and reason both are correct statements and reason is correct

explanation for assertion. (B) Assertion and reason both are correct statements but reason is not correct

explanation for assertion. (C) Assertion is correct statement but reason is wrong statement.


41

(i) Assertion: Low concentration of nucleophile favoursSN1mechanism. Reason:2°alkylhalides are less reactive than 1° towards SN1 reactions. (ii) Assertion: Polar solvent slowsdown SN2 reactions. Reason: CH3-Br is less reactive than CH3Cl (iii) Assertion: Benzyl bromide when kept in acetone-water it produces benzyl alcohol.

Reason: Benzyl bromide undergoes nucleophilicsubstitution reaction by SN2 mechanism.

(iv) Assertion: Rate of hydrolysis of methyl chloride to methanol is higher in DMF than inwater. Reason: Hydrolysis of methyl chloride follows second order kinetics.

(v) Assertion: SN2 reaction of an optically active alkyl halide with an aqueous solution of

KOH always gives an alcohol with opposite sign of rotation. Reason:SN2 reactions always proceed with inversion of configuration.

CASEBASEDA/RQUESTIONS-II


The aryl halides are relatively less reactive towards nucleophilic substitution reactions as compared to alkylhalides.This low reactivity can be attributed to

the following factors: 1. The C - X bond in halobenzene has a partial double bond character due to involvement

of halogen electrons in resonance with benzene ring. 2. The C - X bond in aryl halides is less polar as compared to that in alkyl halides as sp2 hyridised carbon is more electronegative than sp3 hybridised carbon. In these questions( i-v),a statement of assertion followed by a statement of reason is given.


(A) Assertion and reason both are correct statements and reason is correct explanation for assertion.

(B) Assertion and reason both are correct statements but reason is not correct explanation for assertion. (C) Assertion is correct statement but reason is wrong statement. (D) Assertion is wrong statement but reason is correct statement.

(i) Assertion: Primary benzylic halides are more reactive than primary alkyl halides

Towards SN1 reactions.

Reason: Reactivity depends upon the nature of the nucleophile and the solvent.

(ii) Assertion : is less reactive than towards nucleophilic substitution

reactions by SN1mechanism.

Reason:Tertiary alkyl halides react predominantly by SN1 mechanism.

(iii) Assertion: Chlorobenzene is more reactive than p-chloroanisole to nucleophilic

substitution reactions.

Reason: Greater the stability of carbanion, greater is its ease of formation and

hence, more reactive is the aryl halide.

(iv) Assertion: Chlorobenzene is less reactive than benzene towards the electrophilic

substitution reaction.

Reason: Resonance Effect of ‗Cl‘ activates benzene ring towards electrophilic

substitution.

42

(v) Assertion:The C–Cl bond length in chlorobenzene is shorter than that in CH3–Cl.

Reason: In haloarenes Cl is attached to sp2 hyridised carbon which is more

electronegative than sp3 hybridisedcarbon.

[SECTION – C] :ASSERTION–REASONING QUESTIONS

In the following questions a statement of assertion followed by a statement

of reason is given.Choose the correct answer out of the following choices.

(A) Assertion and reason both are correct and reason is correct explanation of

assertion.

(B) Assertion and reason both are correct statements but reason is not correct

explanation of assertion

(C) Assertion is correct but reason is wrong statement.

(D) Assertion is wrong but reason is correct statement.

(E) Assertion and reason both are wrong statements.

1. Assertion : Phosphorus chlorides (tri and penta) are preferred over thionyl chloride for

the preparation of alkyl chlorides from alcohols.

Reason: Phosphoruschlorides give pure alkyl halides.

2. Assertion : The boiling points of alkyl halides decrease in the order :RI >RBr>RCl>RF

Reason : The boiling points of alkyl chlorides, bromides and iodides are

considerably higher than that of the hydrocarbon of comparable

molecular mass.

3. Assertion : KCN reacts with methyl chloride to give methyl isocyanide

Reason: CN– is an ambident nucleophile.

4. Assertion : tert-Butyl bromide undergoes Wurtz reaction to give 2, 2, 3, 3-

tetramethylbutane.

Reason : In Wurtz reaction, alkyl halides react with sodium in dry ether to give

Hydrocarbon containing double the number of carbon atoms present

in the halide.

5. Assertion : Presence of a nitro group at ortho or para position increases the

reactivity of haloarenes towards nucleophilic substitution.

Reason : Nitro group, being an electron withdrawing group decreases the electron

density over the benzenering.

6. Assertion : In mono haloarenes, further electrophilic substitution occurs at ortho and

para positions.

Reason: Halogen atom is a ring deactivator.

43

7. Assertion : Aryl iodides can be prepared by reaction of arenes with iodine in the

presence of an oxidising agent.

Reason: Oxidising agent oxidises I2 into HI.

8. Assertion : It is difficult to replace chlorine by –OH in chlorobenzene in comparison to

that in chloroethane.

Reason : Chlorine-carbon (C—Cl) bond in chlorobenzene has a partial double bond

character due to resonance.

9. Assertion : Hydrolysis of (–)-2-bromooctane proceeds with inversion of configuration.

Reason:This reaction proceeds through the formation of a carbocation.

10. Assertion: Nitration of chlorobenzene leads to the formation of m-nitrochlorobenzene

Reason:—NO2 group is a m-directing group.

[SECTION –D]MCQ:Choosethemostappropriateanswer

1. AmongthefollowingcompoundswhichoneundergoesSN1substitutionreactionfaster?

(A)

(B)

(C)

(D)

2. The order of reactivity of following alcohols with halogen acids is .

A) A>B>C

B) A<B<C

C) A>C>B

D) B>A>C

3. Which of the following alcohols will yield the corresponding alkyl chloride on reaction

with concentrated HCl at room temperature?

A) Pentan-1-ol

44

B) Pentan-2-ol

C) 2-Methylbutan-1-ol

D)2-Methylbutan-2-ol

4. Identify the compound Y in the following reaction.

A) (i)

B) (ii)

C) (iii)

D) (iv)

5. Toluene reacts with a halogen in the presence of iron (III) chloride giving ortho and para halocompounds.The reaction is

(A) Electrophiliceliminationreaction

(B) Electrophilicsubstitutionreaction

(C) Freeradicaladditionreaction

(D) Nucleophilicsubstitutionreaction

6. Which of the following is halogen exchange reaction?

A) i, ii and iii

B) ii,iii and iv

C) only i

D) only iv

45

7. Which reagent will you use for the following reaction?

(A) Cl2/UVlight

(B) NaCl+H2SO4 (C) Cl2 gas in dark (D) Cl2gas in the presence of iron in dark

8. Which of the following compounds will form when Bromo ethane reacts with Mg in

presence of dry ether

A) CH3-CH3

B) CH3-CH2MgBr

C) CH3MgBr

D)(CH3)2MgBr

9. Arrange the following compounds in increasing order of their boiling points

(A) c<a<b

(B) b>a>c

(C) a>b>c

(D) c<b<a

10. In which of the following molecules carbon atom marked with as(*)is asymmetric?

(A)(a),(b),(c),(d)

(B)(a),(b),(c)

(C)(b),(c),(d)

(D)(a),(c),(d)

11. Which of the following is an example of vic-dihalide?

(A) Dichloromethane

(B) 1,2-dichloroethane

(C) Ethylidenechloride

(D) Allylchloride

12. The position of–Br in the compound in CH3CH=CHC(Br)(CH3)2can be classified as

(A) Allyl

(B) Aryl

(C) Vinyl

(D) Secondary

46

13. Chlorobenzene is formed by reaction of chlorine with benzene in the presence of

AlCl3.Which of the following species attacks the benzene ring in this reaction?

(A) Cl–

(B) Cl+

(C) AlCl3

(D) [AlCl4]–

14. Ethylidenechloride is a/an .

(A) vic-dihalide

(B) gem-dihalide

(C) allylichalide

(D) vinylichalide

15. What is ‗A‘ in the following reaction?

A) iii and iv

B) ii, iii and iv

C) only i

D) only iii

16.A primary alkylhalide would prefer to undergo .

(A) SN1 reaction

(B) SN2 reaction

(C) α–Elimination

(D) Racemisation

17. Which of the following alkyl halides will undergo SN1 reaction most readily?

(A) (CH3)3C—F

(B) (CH3)3C—Cl

(C) (CH3)3C—Br

(D) (CH3)3C—I

47

18. What is the correct IUPAC name of CH3-CH(C2H5)CH2-Br

(A) 1-Bromo-2-ethylpropane (B) 1-Bromo-2-ethyl-2-methylethane (C) 1-Bromo-2-methylbutane

(D) 2-Methyl-1-bromobutane

19. What should be the correct IUPAC name for diethylbromomethane?

(A) 1-Bromo-1,1-diethoxyethane

(B) 3-Bromopentane (C) 1-Bromo-1-ethylpropane (D) 1-Bromopentane

20. The reaction of toluene with chlorine in the presence of iron and in the absence of

light yields .

A) Benzylchloride

B) o-Chlorobenzene

C) p-Cholorobenzene D) MixtureofBand C

21. Chloromethane on treatment with excess of ammonia yields mainly

A) N,N-Dimethylmethanamine B) N-Methylmethanamine C) Methanamine

D) Mixtureofalltheabovecompounds

22. Molecules whose mirror image is non superimposable over them are known as

chiral. Which of the following molecules is chiral in nature?

(A) 2-Bromobutane

(B) 1-Bromobutane

(C) 2-Bromopropane

(D) 2-Bromopropan-2-ol 23. Reaction of C6H5CH2Br with aqueous sodium hydroxide follows .

(A) SN1mechanism

(B) SN2mechanism

(C) Any of the above two depending upon the temperature of reaction

(D) Saytzeffrule

24. Which is the correct increasing order of boiling points of the following

compounds?1-Iodobutane,1-Bromobutane,1-Chlorobutane,Butane

(A) Butane<1-Chlorobutane<1-Bromobutane<1-Iodobutane

(B) 1-Iodobutane<1-Bromobutane<1-Chlorobutane<Butane

(C) Butane<1-Iodobutane<1-Bromobutane<1-Chlorobutane

(D) Butane<1-Chlorobutane<1-Iodobutane<1-Bromobutane

48

25. Haloalkanes contain halogen atom (s) attached to the sp3hybridised carbon atom of

an alkyl group. Identify haloalkanes from the following compounds.

(A) 2-Bromopentane

(B) Vinylchloride(chloroethene)

(C) 2-chloroacetophenone

(D) chlorobenzene

26. Which of the following compounds is unsaturated?

(A) Ethylidenechloride

(B) ChloroEthylene

(C) Methylchloride

(D) Benzylchloride

27. Alkylhalides are prepared from alcohols by treating with

(A) HCl+ZnCl2

(B) RedP+Br2

(C) PCl5

(D) Alltheabove

28. Alkylfluorides are synthesized by heating an alkylchloride/bromide in presence of

(A) CaF2

(B) PF3

(C) Hg2F2

(D) NaF

49

29. Match the structures given in Column I with the names in Column II.

A) i-a,ii-b,iii-c,iv-d

B) i-b,ii-a,iii-d,iv-c

C) ) i-d,ii-b,iii-c,iv-a

D) i-a,ii-d,iii-c,iv-b

30. Match the reactions given in Column I with the names given in ColumnII.

A) i-a,ii-b,iii-c,iv-d

B) i-b,ii-a,iii-d,iv-c

C) ) i-d, ii-b,iii-c,iv-a

D) i-c,ii-a,iii-b,iv-d

50

ANSWERS:

SECTIONACASEBASEDMCQ:

Q.NO1

Q.NO2

Q.NO3

i)B

i)C

i)A

ii)D

ii)C

ii)A

iii)B

iii)Aiii)

C

iv)D

iv)Div)C

v)D

v)A

v)D

SECTIONBCASEBASEDA/R

Q.NO1i)C

ii)C

iii)A

iv)D

v)A

Q.NO2i)A ii)D iii)A iv)C v)B

SECTION C A/R

1E 2B 3D 4A 5A 6B 7C 8A 9C 10D

SECTION DMCQ

1C 2B 3D 4A 5B 6C 7A 8B 9A 10B

11B 12D 13B 14B 15D 16B 17D 18C 19B 20D

21C 22A 23A 24A 25A 26B 27D 28C 29A 30B

51

5. ALCOHOLS, PHENOLS AND ETHERS

SECTION – A

CASE BASED MCQ – 1

In alcohols, the oxygen of the –OH group is attached to carbon by a sigma (s ) bond formed by the overlap of a sp3hybridised orbital of carbon with a sp3hybridised orbital

of oxygen. Figure given below depicts structural aspects of methanol, phenol and methoxymethane.

1. The bond angle C-O-H in alcohols is slightly less than the tetrahedral angle

(109°28‘). It is due to –

(A) The attraction between C-O and O-H bond pairs. (B) The repulsion between the unshared electron pairs of oxygen.

(C) The repulsion between neighbouring C-H bonds. (D) The high electronegativity of oxygen.

2. In phenols, the –OH group is attached to ____ hybridised carbon of an aromatic

ring. (A) sp3

(B) sp (C) dsp2 (D) sp2

3. The C – O bond length in phenol is slightly less than that in methanol. This is due to –

(A) Partial double bond character on account of the conjugation of unshared electron pair of oxygen with the aromatic ring.

(B) Presence of heavier group – phenol.

(C) Positioning of lone pair over oxygen in 3 – D space. (D) sp3hybridised state of carbon to which oxygen is attached.

4. The bond angle in ethers is slightly greater than the tetrahedral angle due to – (A) Presence of four electron pair around the oxygen. (B) The repulsive interaction between the two bulky (–R) groups.

(C) Absence of O – H bond. (D) The attractive interaction between the two bulky (–R) groups.

5. In methoxymethane, the oxygen atom is ____ hybridised. (A) sp3 (B) sp

(C) dsp2 (D) sp2

52

CASE BASED MCQ – 2 The boiling points of alcohols and phenols increase with increase in the number of

carbon atoms (increase in van der Waals forces). In alcohols, the boiling points decrease with increase of branching in carbon chain (because of decrease in van der Waals forces with decrease in surfacearea). The –OH group in alcohols and phenols is

involved in intermolecular hydrogen bonding as shown below:

It is interesting to note that boiling points of alcohols and phenols are higher in

comparison to other classes of compounds, 1. The high boiling points of alcohols as compared to hydrocarbons and ethers are

mainly due to the –

(A) Presence of intramolecular hydrogen bonding. (B) High molecular mass.

(C) High volatile nature. (D) Presence of intermolecular hydrogen bonding.

2. On comparing the boiling points of ethanol, propane and methoxymethane –

(A) Ethanol has intermediate boiling point. (B) Propane has intermediate boiling point.

(C) Methoxymethane has intermediate boiling point. (D) Methoxymethane and propane have same boiling points.

3. Why does tertiary butyl alcohol has lower boiling point than n-butyl alcohol?

(A) Intramolecular hydrogen bonding in tertiary butyl alcohol. (B) Smaller surface area and lesser van der Waal forces in tertiary butyl

alcohol. (C) Intramolecular hydrogen bonding in n-butyl alcohol.

(D) Smaller surface area and lesser van der Waal forces in n-butyl alcohol. 4. Arrange the following compounds in increasing order of their boiling point.

Propan-1-ol, Butan-1-ol, Butan-2-ol and Pentan-1-ol.

(A) Propan-1-ol, Butan-2-ol, Butan-1-ol and Pentan-1-ol. (B) Propan-1-ol, Butan-1-ol, Butan-2-ol and Pentan-1-ol.

(C) Pentan-1-ol, Butan-2-ol, Butan-1-ol and Propan-1-ol. (D) Pentan-1-ol, Butan-1-ol, Butan-2-ol and Propan-1-ol.

5. Arrange the following compounds in increasing order of their boiling point. Pentanal, n-Butane, Ethoxyethane and Pentan-1-ol.

(A) Pentanal, n-Butane, Ethoxyethane, Pentan-1-ol. (B) Pentanal, Ethoxyethane, n-Butane, Pentan-1-ol. (C) n-Butane, Pentanal, Ethoxyethane, Pentan-1-ol.

(D) n-Butane, Ethoxyethane, Pentanal, Pentan-1-ol.

53

CASE BASED MCQ – 3 By a proper choice of reagents, both symmetrical and unsymmetrical ethers can be

prepared by Williamson synthesis which involves the reaction between an alkyl halide and and an alkoxide ion. The reverse process involves the cleavage of ethers to give back the original alkyl halide and the alcohol can be carried out by heating the ether

with HI at 373 K. 1. The mechanism of Williamson synthesis involves –

(A) Nucleophilic substitution bimolecular (B) Nucleophilic substitution unimolecular (C) Electrophilic substitution bimolecular

(D) Electrophilic substitution bimolecular 2. Benzyl ethyl ether reacts with HI to form –

(A) p-iodotoluene and ethyl alcohol. (B) Benzyl alcohol and ethyl iodide. (C) Benzyl iodide and ethyl alcohol.

(D) Iodobenzene and ethyl alcohol. 3. Allyl phenyl ether can be prepared by heating –

(A) C6H5Br + CH2=CH-CH2ONa (B) CH2=CHCH2Br + C6H5ONa (C) C6H5CH=CHBr + CH3ONa

(D) CH2=CHBr + C6H5CH2ONa 4. Better results are obtained if the alkyl halide is primary. In caseof secondary

and tertiary alkyl halides – (A) Steric hinderance is more.

(B) Elimination competes over substitution. (C) C-X bond is stronger. (D) Generation of electrophile is difficult.

5. Which of the following ethers are not cleaved by HI? (A) Dicyclohexyl ether

(B) Ethyl phenyl ether (C) Di – tert – butyl ether (D) Diphenyl ether

SECTION – B

CASE BASED A-R TYPE MCQ - 1

Instructions – In the following questions, a statement of assertion followed by a statement of

reason is given. Choose the correct answer out of the following choices. (A) Both assertion and reason are true and the reason is the correct explanation of assertion.

(B) Both assertion and reason are true but the reason is not the correct explanation of assertion.

(C) Assertion is true but reason is false. (D) Assertion is false but reason is true. Alcohols and phenols are acidic in nature. In fact, alcohols and phenols are Brönsted

acids i.e., they can donate a proton to a stronger base (B:).The acidic character of alcohols and phenols is due to the polar nature of O–H bond. Alcohols are, however,

weaker acids than water. The reaction of phenol with aqueous sodium hydroxide indicates that phenols are stronger acids than alcohols and water. In substituted

54

phenols, the presence of electron withdrawing groups such as nitro group, enhances the acidic strength. On the other hand, electron releasing groups result in decrease in acid strength. This effect is more pronounced when such a group is present at ortho

and para positions. 1. Assertion – p- Nitrophenol is a stronger acid than o-Nitrophenol.

Reason – Intramolecular hydrogen bonding makes o-isomer weaker than p-isomer.

2. Assertion – p-Florophenol is less acidic than p-chlorophenol. Reason – F exerts better +mesomeric effect than Cl.

3. Assertion – m-Methoxyphenol is a stronger acid than p-Methoxyphenol.

Reason – Methoxy group exerts +R effect at both ortho and para positions. 4. Assertion – Ethanol is a weaker acid than phenol.

Reason – Sodium ethoxide may be prepared by the reaction of ethanol with aqueous NaOH.

5. Assertion – Water is weaker acid than alcohols.

Reason - Alkoxide ion is a better proton acceptor than hydroxide ion.

CASE BASED A-R TYPE MCQ - 2 Instructions – In the following questions, a statement of assertion followed by a statement of

reason is given. Choose the correct answer out of the following choices. (A) Both assertion and reason are true and the reason is the correct explanation of

assertion. (B) Both assertion and reason are true but the reason is not the correct

explanation of assertion. (C) Assertion is true but reason is false. (D) Assertion is false but reason is true.

Alcohols undergo dehydration to form alkenes on treating with a protic acid e.g. concentrated H2SO4, or catalysts such as anhydrous zincchloride or alumina. Ethanol

undergoes dehydration by heating it with concentratedH2SO4 at 443 K. Secondary and tertiary alcohols are dehydrated under milder conditions. The mechanism of dehydration of ethanol involves the following steps:

55

1. Assertion – The ease of dehydration of alcohols follow the order - 1°>2°>3°. Reason – Dehydration process proceeds through the formation of carbocation.

2. Assertion– 2-Butanol on heating with conc. H2SO4 gives 1-Butene and 2-

Butene. Reason – In dehydration of 2-Butanol the preferred product is that alkene

which has the greater number of alkyl groups attached to the doubly bonded carbon atoms.

3. Assertion – tert-Butyl alcohol undergoes acid catalysed dehydration readily than propanol. Reason – Tertiary alcohols have greater steric hindrance.

4. Assertion – Methanol does not give a stable compound on dehydration. Reason – Carbene is highly unstable.

5. Assertion – Dehydration of alcohols form alkanes. Reason – Dehydration of alcohols involve elimination reaction.

SECTION – C

A-R TYPE MCQ Instructions –

In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.

(A) Both assertion and reason are true and the reason is the correct explanation of assertion. (B) Both assertion and reason are true but the reason is not the correct

explanation of assertion. (C) Assertion is true but reason is false.

(D) Assertion is false but reason is true.

1. Assertion – In case of phenol, bromination takes place even in absence of

Lewis acid whereas bromination of benzene takes place in presence of Lewis

acid like FeBr3.

Reason – OH group attached to benzene ring is highly deactivating. 2. Assertion – Ethers behave as bases in the presence of mineral acids.

Reason –Oxygen has two lone pairs of electrons. 3. Assertion – With HI, anisole gives iodobenzene and methyl alcohol.

Reason – Iodide ion combines with smaller group to avoid steric hindrance.

4. Assertion – Phenol is more reactive than benzene towards electrophilic substitution reaction.

Reason – In the case of phenol, the intermediate carbocation is more resonance stabilized.

5. Assertion – Reimer-Tiemann reaction of phenol with CCl4 in NaOH at 340 K

gives salicyclic acid as the major product. Reason – The reaction occurs through intermediate formation of

dichlorocarbene. 6. Assertion – Phenols give o-nitrophenol and p-nitrophenol on nitration with

conc. HNO3 and H2SO4 mixture.

Reason – OH group in phenol is o, p – directing. 7. Assertion – 2-pentanol and 3-pentanol cannot be distinguished by iodoform

test. Reason – 2-pentanol and 3-pentanol both are secondary alcohols.

8. Assertion – Benzene diazonium chloride on boiling with water gives phenol. Reason – C-N bond is polar.

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9. Assertion – Reaction of alcohols with SOCl2 is catalysed by the presence of tertiary amine. Reason – Tertiary amine promotes the reaction by reacting with the by

product HCl 10.Assertion – Solubility of alcohols decreases with increase in the size of

alkyl/aryl groups. Reason – Alcohols form hydrogen bonding with water to show soluble nature.

SECTION – D

MCQ

1. Among the following compounds, strongest acid is –

(A) H-C = C-H

(B) C6H6 (C) C2H6

(D) CH3OH 2. In the following compounds:

The order of acidity is

(A) c > d > a > b (B) a > d > c > b (C) b > a > c > d

(D) d > c > a > b 3. Which of the following is most acidic?

(A) Phenol (B) Benzyl alcohol (C) m-chlorophenol

(D) Cyclohexanol 4. In the reaction of phenol with CHCl3 and aqueous NaOH at 343 K, the

electrophile attacking the ring is – (A) CHCl3 (B) CHCl2

(C) CCl2 (D) COCl2

5. The ether

when treated with HI produces

(A) Benzyl iodide (B) Benzyl alcohol (C) Iodobenzene

(D) Phenol

57

6. 1-Propanol and 2-propanol can be best distinguished by – (A) Oxidation with KMnO4 followed by reaction with Fehling solution. (B) Oxidation with acidic dichromate followed by reaction with Fehling

solution. (C) Oxidation by heating with copper followed by reaction with Fehling

solution. (D) Oxidation with cone. H2SO4 followed by reaction with Fehling solution.

7. Phenol reacts with Br2 in CS2 at low temperature to give – (A) o-Bromophenol (B) o-and p-Bromophenols

(C) p-Bromophenol (D) 2, 4, 6 -Tribromophenol

8. The compound which gives the most stable carbonium ion on dehydration is – (A) (CH3)2CHCH2OH (B) (CH3)3COH

(C) CH3CH2CH2CH2OH (D) CH3CH OH CH2 CH3

9. In the following reaction

→

(A) Ethane (B) Ethylene

(C) Butane (D) Propane

10.Which of the following cannot be made by using Williamson Synthesis – (A) Methoxybenzene (B) Benzyl p-nitrophenyl ether

(C) tert. butyl methyl ether (D) Ditert. butyl ether

11.Among the following, the one which reacts most readily with ethanol is – (A) p-Nitrobenzyl bromide (B) p-Chlorobenzyl bromide

(C) p-Methoxybenzyl bromide (D) p-Methyl benzyl bromide

12. Cyclohexene is best prepared from cyclohexanol by which of the following – (A) Conc. H3PO4

(B) Conc. HCl/ZnCl2

(C) Conc. HCl (D) Conc. HBr

13.Acetone reacts with Grignard reagent to form – (A) 3° alcohol

(B) 2° alcohol (C) Ether

(D) No reaction 14.Phenol on reduction with H2 in the presence of Ni catalyst gives –

(A) Benzene

(B) Toluene (C) Cyclohexane

(D) Cyclohexanol

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15.The alcohol which does not react with Lucas reagent is – (A) isobutyl alcohol (B) n-butanol

(C) tert-butyl alcohol (D) sec-butyl alcohol

16.During dehydration of alcohols to alkenes by heating with cone. H2SO4 the initial step is –

(A) Formation of an ester (B) Protonation of alcohol molecule (C) Formation of carbocation

(D) Elimination of water 17.The product of acid catalysed hydration of 2-phenylpropene is –

(A) 3-Phenyl-2-propanol (B) 1-Phenyl-2-propanol (C) 2-phenyl-2-propanol

(D) 2-phenyl-1-propanol 18.Oxygen containing organic compounds upon oxidation forms a carboxylic acid

as the only organic product with its molecular mass higher by 14 units. What is the organic compound?

(A) A primary alcohol

(B) A ketone (C) An aldehyde

(D) A secondary alcohol 19.An organic compound with a pleasant odour and 78 degrees boiling point is

boiled with concentrated H2SO4. It gives a colourless gas which decolorizes

bromine water and alkaline potassium permanganate. What is this organic compound?

(A) C2H5COOCH3 (B) C2H5OH (C) C2H5Cl

(D) C2H6 20.Which of the following is true?

(A) Lower alcohols are liquid at room temperature and the higher ones are solid

(B) Lower alcohols and higher alcohols, both are liquid at room temperature

(C) Higher alcohols are liquid at room temperature and the lower ones are solid

(D) Both lower and higher alcohols are solid at room temperature 21.How many alcohols with molecular formula C4H10O are chiral in nature?

(A) 1

(B) 2 (C) 3

(D) 4

22.IUPAC name of m-cresol is – (A) 3-methylphenol (B) 3-chlorophenol

(C) 3-methoxyphenol (D) Benzene-1,3-diol

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23.Which of the following compounds is aromatic alcohol?

(A) a, b, c, d (B) a, d

(C) b, c (D) a

24.Which of the following compounds will react with sodium hydroxide solution in water?

(A) C6H5OH (B) C6H5CH2OH (C) (CH3)3COH

(D) C2H5OH 25.Monochlorination of toluene in sunlight followed by hydrolysis with aq. NaOH

yields – (A) o-Cresol (B) m-Cresol

(C) 2, 4-Dihydroxytoluene (D) Benzyl alcohol

26.Mark the correct increasing order of reactivity of the following compounds with

HBr/HCl.

(A) a < b < c (B) b < a < c

(C) b < c < a (D) c < b < a

27.How many isomers of C5H11OH will be primary alcohol?

(A) 4

(B) 3 (C) 5

(D) 2

28.Benzyl alcohol is obtained from benzaldehyde by –

(A) Wurtz reaction (B) Fittig reaction

(C) Kolbe‘s reaction (D) Cannizaro reaction

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29.In the following sequence of reactions, The compound D is–

→

→

→

→

(A) Butanal

(B) n-Butyl alcohol (C) n-Propyl alcohol

(D) Propanal 30.In CH3CH2OH, the bond that undergoes heterolytical change most readily is –

(A) C-C

(B) C-O

(C) C-H

(D) O-H

ANSWER KEY CASE BASED MCQ – 1

1. (B) 2. (D) 3. (A)

4. (B) 5. (A)

CASE BASED MCQ – 2 1. (D)

2. (C) 3. (B)

4. (A)

5. (D)

CASE BASED MCQ – 3

1. (A) 2. (C)

3. (B), C6H5OCH2CH=CH2is allyl phenyl ether. 4. (B) 5. (D), In diphenyl ether, oxygen atom is bonded to phenyl ring and both bonds

are strong. They cannot be cleaved by HI.

CASE BASED A-R TYPE MCQ - 1 1. (A)

2. (A) 3. (B) 4. (C), Ethanol does not react with dilute sodium hydroxide because ethoxide ion

is a stronger base than hydroxide ion.. 5. (D), Water is stronger acid than alcohols.

CASE BASED A-R TYPE MCQ – 2

1. (D)

2. (A)

3. (B)

4. (A)

5. (D), Dehydration

6. of alcohols form alkenes.

A – R TYPE MCQ

1. (C), OH group in phenol is activating. 2. (A) 3. (D),With HI, anisole gives phenol and methyliodide

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4. (A) 5. (C), The reaction occurs through intermediate formation of dichlorocarbene by

chloroform

6. (D), Phenols give o-nitrophenol and p-nitrophenol on nitration with conc. HNO3 only.

7. (D), 2-pentanol and 3-pentanol can be distinguished by iodoform test.2-pentanolgives + iodoform test.

8. (B) 9. (A) 10.(B)

MCQ

1. (D) 2. (D) 3. (C)

4. (C) 5. (A)

6. (C) 7. (B) 8. (B)

9. (A) 10.(D)

11.(C) 12.(A) 13.(A)

14.(D) 15.(B)

16.(B) 17.(C) 18.(A)

19.(B) 20.(A)

21.(A) 22.(A) 23.(B)

24.(A) 25.(D)

26.(C) 27.(A) 28.(D)

29.(C) 30.(D)

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6. Biomolecules

[SECTION- A]

CASE STUDY BASED MCQ-I

I. Read the passage given below and answer the following questions:(1×4 = 4) The basic chemical formula of DNA is now well established. It consists of a very long

chain, the backbone of which is made up of alternate sugar and phosphate groups, joined together in regular 3‘ 5‘ phosphodiester linkages. To each sugar is attached a nitrogenous base, only four different kinds of which are commonly found in DNA. Two

of these---adenine and guanine--- are purines, and the other two thymine and cytosine-are pyrimidines. A fifth base, 5-methyl cytosine, occurs in smaller amounts in

certain organisms, and a sixth, 5-hydroxy-methyl-cytosine, is found instead of cytosine in the T even phages. It should be noted that the chain is unbranched, a consequence of the regular internucleotide linkage. On the other hand the sequence of

the different nucleotides is, as far as can be ascertained, completely irregular. Thus, DNA has some features which are regular, and some which are irregular. A similar

conception of the DNA molecule as a long thin fiber is obtained from physicochemical analysis involving sedimentation, diffusion, light scattering, and viscosity

measurements. These techniques indicate that DNA is a very asymmetrical structure approximately 20 A wide and many thousands of angstroms long. Estimates of its molecular weight currently center between 5 X106 and X107 (approximately 3 X104

nucleotides). Surprisingly each of these measurements tend to suggest that the DNA is relatively rigid, a puzzling finding in view of the large number of single bonds (5 per

nucleotide) in the phosphate-sugar back bone. Recently these indirect inferences have been confirmed by electron microscopy. Q. 1. Purines present in DNA are:

(A) adenine and thymine (B) guanine and thymine

(C) cytosine and thymine (D) adenine and guanine Q. 2. DNA molecule has ___________ inter nucleotide linkage and __________

sequence of the different nucleotides . (A) regular, regular (B) regular, irregular

(C) irregular, regular (D) irregular, irregular Q. 3. DNA has a ___________ backbone (A) phosphate-purine (B) pyrimidines-sugar

(C) phosphate-sugar (D) purine-pyrimidine Q. 4. Out of the four different kinds of nitrogenous bases which are commonly found

in DNA, ___________ has been replaced in some organisms. (A) adenine (B) guanine (C) cytosine (D) thymine

CASE STUDY BASED MCQ-II

2. Read the passage given below and answer the following questions:(1×4= 4) The two monosaccharides are joined together by an oxide linkage formed by the loss

of a water molecule. Such a linkage between two monosaccharide units through oxygen atom is called glycosidic linkage. In disaccharides, if the reducing groups of monosaccharides i.e., aldehydic or ketonic groups are bonded, these are non-reducing

63

sugars, e.g., sucrose. On the other hand, sugars in which these functional groups are free, are called reducing sugars, for example, maltose and lactose. A non reducing disaccharide ‗A‘ on hydrolysis with dilute acid gives an equimolar mixture of D–(+)–

glucose and D-(-)-Fructose. Q. 1. In the above reaction, reactant ‗A‘ is:

(A) Glucose (B) Sucrose (C) Maltose (D) Fructose Q. 2. What is the mixture of D-(+) glucose and D-(-) fructose known as ?

(A) Anomers (B) Racemic mixture (C) Invert sugar (D) Optical mixture Q. 3. Name the linkage that holds the two units in the disaccharide ?

(A) Nucleoside linkage (B) Glycosidic linkage (C) Peptide linkage (D) None of the above

Q. 4. Glucose on reaction with acetic acid gives glucose pentaacetate. What does it suggest about the structure of glucose ? (A) C-1 is anomeric carbon (B) C-5 is anomeric carbon

(C) 3‘-OH groups are present (D) 5‘-OH groups are present OR

Proteins are found to have two different types of secondary structures, viz. a-helix and b-pleated sheet structure. a-helix structure of protein is stabilised by (A) Peptide bonds (B) van der Waals forces

(C) Hydrogen bonds (D) Dipole-dipole interactions

CASE STUDY BASED MCQ-III

3. Read the passage given below and answer the following questions:(1×4= 4) The sequence of bases in m-RNA are read in a serial order in groups of three at a time. Each triplet of nucleotides (having a specific sequence of bases) is known as

codon. Each codon specifies one amino acid. Many amino acids have more than one codons. The amino acids are brought to the mRNA by another type of RNA and called

t-RNA. Each amino acid has atleast one corresponding t-RNA. At one end of the t-RNA molecule is a trinucleotide base sequence that is complementary to some trinucleotide base sequence on m-RNA.

Q. 1. Which of the following nitrogen bases is not present in RNA? (A) Thymine (B) Adenine (C) Guanine (D) Cytosine

Q. 2. Each triplet of nucleotides is called: (A) Anticodon (B) Codon (C) m-RNA (D) t-RNA Q. 3. Each codon specifies:

(A) 1 amino acid (B) 2 amino acids (C) 3 amino acids (D) None of these Q. 4. In mRNA, the complementary bases of AAT is:

(A) CCG (B) UUA (C) AUU (D) UUU OR The amino acids are brought to the mRNA by:

(A) r-RNA (B) DNA (C) t-RNA (D) None of these.

[SECTION – B]

CASE STUDY BASED (A-R)

In the following questions a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choice.

(A) Assertion and reason both are correct statements but reason is correct explanation for assertion.

64

(B)Assertion and reason both are correct statements but reason is not correct explanation for assertion. (C)Assertion is correct statements but reason is wrong statement.

(D)Assertion is wrong statement but reason is correct.

CASE STUDY BASED (A-R)-I 1. Read the passage given below and answer the following questions:(1×4= 4)

Complete hydrolysis of DNA (or RNA) yields a pentose sugar, phosphoric acid and nitrogen containing heterocyclic compounds (called bases). In DNA molecules, the sugar moiety is β-D-2-deoxyribose whereas in RNA molecule, it is β-D-ribose.DNA

contains four bases viz. adenine (A), guanine (G), cytosine (C) and thymine (T). RNA also contains four bases, the first three bases are same as in DNA but the fourth one

is uracil (U). A unit formed by the attachment of a base to 1′ position of sugar is known as nucleoside. In nucleosides, the sugar carbons are numbered as 1′, 2′, 3′, etc. in order

to distinguish these from the bases. When nucleoside is linked to phosphoric acid at 5′-position of sugar moiety, we get a nucleotide. Nucleotides are joined together by

phosphodiester linkage between 5′ and 3′ carbon atoms of the pentose sugar. Information regarding the sequence of nucleotides in the chain of a nucleic acid is called its primary structure. Nucleic acids have a secondary structure also. James

Watson and Francis Crick gave a double strand helix structure for DNA. Two nucleic acid chains are wound about each other and held together by hydrogen bonds

between pairs of bases. The two strands are complementary to each other because the hydrogen bonds are formed between specific pairs of bases. Adenine forms

hydrogen bonds with thymine whereas cytosine forms hydrogen bonds with guanine. In secondary structure of RNA single stranded helices is present which sometimes folds back on itself. RNA molecules are of three types and they perform different

functions. They are named as messenger RNA (m-RNA), ribosomal RNA (r-RNA) and transfer RNA (t-RNA)

Q. 1. Assertion: On hydrolysis of DNA, the quantity of adenine produced is equal to that of thymine and similarly, the quantity of cytosine is equal to that of guanine.

Reason: A DNA molecule is double-stranded in which the pairing of bases occurs.

Adenine always pairs with thymine, while cytosine always pairs with guanine.

Q. 2. Assertion: When a nucleotide from the DNA containing thymine is hydrolyzed,

thymine β-D- 2-deoxyribose and phosphoric acid are obtained as products.

Reason: When a nucleotide from the DNA containing thymine is hydrolyzed, β-D- 2-ribose and phosphoric acid are obtained as products.

Q. 3. Assertion: When RNA is hydrolysed, there is no relationship among the quantities of different bases obtained.

Reason: when RNA is single-stranded.

Q. 4. Assertion: The two strands of DNA are complementary to each other.

Reason: The two strands of DNA contain covalent bonds formed between specific

pairs of bases.

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CASE STUDY BASED (A-R)-II

2. Read the passage given below and answer the following questions :(1×4= 4) When a protein in its native form, is subjected to physical changes like change in temperature or chemical changes like change in pH, the hydrogen bonds are

disturbed. Due to this, globules unfold and helix gets uncoiled and protein loses its biological activity. This is called denaturation of protein.

The denaturation causes change in secondary and tertiary structures but primary structures remains intact. Examples of denaturation of protein are coagulation of egg white on boiling, curding of

milk, and formation of cheese when an acid is added to milk.

Q. 1. Assertion: Amino acids are known as α-amino acids.

Reason: Amino acids are organic compounds containing an amino group and a

carboxylic group as substituent on the α-carbon.

Q. 2. Assertion: Proteins are a hetero-polymer.

Reason: Dietary proteins are the source of non-essential amino acids. Q. 3. Assertion: The long protein chain folds upon itself like a hollow ball giving rise

to the tertiary structure. Reason: Tertiary structure gives a 3-dimensional view of a protein. Q. 4. Assertion: Amino acids are amphoteric in their function.

Reason: All amino acids are necessary for our body.

[SECTION – C]

Assertion-Reason Questions- (1x10 =10) In the following questions (Q.1 to Q.10) a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choice. (A) Assertion and reason both are correct statements but reason is correct

explanation for assertion. (B)Assertion and reason both are correct statements but reason is not correct

explanation for assertion. (C)Assertion is correct statements but reason is wrong statement. (D)Assertion is wrong statement but reason is correct.

Q. 1. Assertion (A): D(+)–Glucose is dextrorotatory in nature. Reason (R): ‗D‘ represents its dextrorotatory nature.

Q. 2. Assertion (A): Deoxyribose, C5H10O4 is not a carbohydrate. Reason (R): Carbohydrates are optically active polyhydroxy aldehyde or polyhydroxy ketone or substances which give aldehyde or ketone on hydrolysis.

Q. 3. Assertion (A): Glucose reacts with hydroxylamine to form an oxime and also adds a molecule of hydrogen cyanide to give cyanohydrin.

Reason (R): The carbonyl group is present in the openchain structure of glucose. Q. 4. Assertion (A): The two strands of DNA are complementary to each other. Reason (R): The hydrogen bonds are formed between specific pairs of bases.

Q. 5. Assertion (A): All naturally occurring α- amino acids except glycine are optically

active.

Reason (R): Most naturally occurring α- amino acids have L-configuration.

Q. 6. Assertion (A): Glycine must be taken through diet. Reason (R): It is non-essential amino acid.

66

Q. 7. Assertion: At isoelectric point, the amino group does not migrate under the influence of electric field. Reason: At isoelectric point, amino acid exists as a zwitterion.

Q. 8. Assertion: Acetic acid have the general formula C2(H2O)2 can be considered as a member of carbohydrates

Reason: Rhamnose is a carbohydrate but do not fit in to the formula C2(H2O)2 . Q. 9. Assertion: Lactose is a reducing sugar.

Reason: All those carbohydrates which reduce Fehling‘s solution are Reducing Sugars. Q. 10. Assertion: Sucrose is called an invert sugar. Reason: On hydrolysis, sucrose bring the change in the sign of rotation from dextro

(+) to laevo(–).

MCQ – (1x30=30) 1.Which of the following statements is not true about glucose?

(A) It is an aldohexose. (B) On heating with HI it forms n-hexane.

(C) It is present in furanose form. (D) It does not give 2,4-DNP test. 2. Nucleic acids are the polymers of ______________.

(A) Nucleosides (B) Nucleotides (C) Bases (D) Sugars 3. Dinucleotide is obtained by joining two nucleotides together by phosphodiester

linkage. Between which carbon atoms of pentose sugars of nucleotides are these linkages present? (A) 5' and 3'

(B) 1' and 5' (C) 5' and 5'

(D) 3' and 3' 4. Each polypeptide in a protein has amino acids linked with each other in a specific sequence. This sequence of amino acids is said to be ____________.

(A) primary structure of proteins. (B) secondary structure of proteins.

(C) tertiary structure of proteins. (D) quaternary structure of proteins. 5. Proteins are found to have two different types of secondary structures viz. alpha-

helix and beeta-pleated sheet structure. α-helix structure of protein is stabilised by:

(A) Peptide bonds

(B) van der Waals forces (C) Hydrogen bonds (D) Dipole-dipole interactions

6. DNA and RNA contain four bases each. Which of the following bases is not present in RNA?

(A) Adenine (B) Uracil (C) Thymine

(D) Cytosine 7. Which of the following bases is not present in DNA?

(A) Adenine (B) Thymine (C) Cytosine

(D) Uracil

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8. Which of the following is an example of aldohexose? (A) Ribose (B) Fructose

(C) Sucrose (D) Glucose

9. Which of the following reactions of glucose can be explained only by its cyclic structure?

(A) Glucose forms pentaacetate. (B) Glucose reacts with hydroxylamine to form an oxime. (C) Pentaacetate of glucose does not react with hydroxylamine.

(D) Glucose is oxidised by nitric acid to gluconic acid. 10. Carbohydrates are classified on the basis of their behaviour on hydrolysis and also

as reducing or non-reducing sugar. Sucrose is a __________. (i) monosaccharide (ii) disaccharide

(iii) reducing sugar (iv) non-reducing sugar

(A)(i) and (iii) (B)(ii) and (iii) (C)(ii) and (iv)

(D)(i) and (iv) 11. Proteins can be classified into two types on the basis of their molecular shape i.e.,

fibrous proteins and globular proteins. Examples of globular proteins are : (i) Insulin (ii) Keratin (iii) Albumin (iv) Myosin (A)(i) and (iii)

(B)(ii) and (iii) (C)(ii) and (iv)

(D)(i) and (iv) 12. Name the sugar present in milk. (A)Glucose

(B) Fructose (C) Lactose

(D)Maltose

13. Glycogen is a branched chain polymer of α-D-glucose units in which chain is

formed by C1-C4 glycosidic linkage whereas branching occurs by the formation of C1-

C6 glycosidic linkage. Structure of glycogen is similar to (A) amylose

(B) amylopectin (C) cellulose (D) glucose

14. Which of the following polymer is stored in the liver of animals? (A) Amylose

(B) Cellulose (C) Amylopectin (D) Glycogen

15. Sucrose (cane sugar) is a disaccharide. One molecule of sucrose on hydrolysisgives

(A) 2 molecules of glucose (B) 2 molecules of glucose + 1 molecule of fructose (C) 1 molecule of glucose + 1 molecule of fructose

68

(D) 2 molecules of fructose 16. Which reagent is used to convert glucose into saccharic acid? (A) Br2/H2O

(B) Nitric acid (C) Alkaline solution of iodine

(D) Ammonium hydroxide 17. Which one is the complementary base of cytosine in one strand to that in other

strand of DNA? (A) Adenine (B) Guanine

(C) Thymine (D) Uracil

18. In disaccharides, if the reducing groups of monosaccharides, i.e., aldehydic or ketonic groups are bonded, these are non-reducing sugars. Which of the following disaccharide is a non-reducing sugar?

19. Glucose is correctly named as D(+)-glucose. ‗D‘ before the name of glucose represents (A) dextrorotatory

(B) configuration (C) diamagnetic nature

(D) mode of synthesis 20. The bond that joins the two alpha-amino acids is called (A) glycosidic linkage

(B) peptide linkage (C) hydrogen bond

(D) ionic bond 21. Identify the correct statement

(A) Cytosine forms hydrogen bond with guanine. (B) Adenine forms hydrogen bond with guanine. (C) Cytosine forms hydrogen bond with thymine.

(D) Adenine forms hydrogen bond with Uracil 22. Curdling of milk is an example of:-

(A) breaking of peptide linkage (B) hydrolysis of lactose

69

(C) breaking of protein into amino acids (D) denaturation of protein 23. Three cyclic structures of monosaccharides are given below which of these are

anomers.

24. Optical rotations of some compounds along with their structures are given below

which of them have D configuration.

25. Structure of a disaccharide formed by glucose and fructose is given below. Identify anomeric carbon atoms in monosaccharide units.

26. Three structures are given below in which two glucose units are linked. Which of these linkages between glucose units are between C1 and C4 and which linkages are between C1 and C6?

70

27. Carbohydrates are classified on the basis of their behaviour on hydrolysis and also as reducing or non-reducing sugar. Sucrose is a .

(A) monosaccharide (B) disaccharide

(C) reducing sugar (D) None of these

28. Proteins can be classified into two types on the basis of their molecular shape, i.e., fibrous proteins and globular proteins. Examples of globular proteins are (A) insulin

(B) keratin (C) Both (a) and (b)

(D) myosin 29. In fibrous proteins, polypeptide chains are held together by:- (A) van der Waals forces

(B) disulphide linkage (C) both A and B

(D) None of these. 30. DNA fingerprinting is now used :- (i) in forensic laboratories for identification of criminals.

(ii) to determine paternity of an individual. (iii) to identify the dead bodies in any accident by comparing the DNA‘s of parents or

children. (iv) to identify racial groups to rewrite biological evolution. (A) i,ii,iv

(B) i,ii,iii (C) ii,iii,iv

(D) All of these *********************************************

71

ANSWER KEY SECTION - A

CASE STUDY BASED (MCQ)

CS-1

1. Ans. Option (D) is correct. 2. Ans. Option (B) is correct.

3. Ans. Option (C) is correct. 4.Ans. Option (C) is correct.

CS-2

1. Ans. Option (B) is correct. 2. Ans. Option (C) is correct.

3. Ans. Option (B) is correct. 4. Ans. Option (D) is correct. OR Option (C) is correct

CS-3

1. Ans. Option (A) is correct. 2. Ans. Option (B) is correct.

3. Ans. Option (A) is correct.

4. Ans. Option (B) is correct. OR Option (C) is correct

SECTION - B CS-1

1. Ans.Option (A) is correct. 2. Ans. Option (C) is correct.

3. Ans. Option (A) is correct. 4.Ans. Option (C) is correct.

CS-2

1. Ans.Option (A) is correct. 2. Ans. Option (C) is correct.

3. Ans. Option (B) is correct. 4.Ans. Option (C) is correct.

SECTION - C

Assertion-Reason Questions 1. C 2. D 3. A 4. A 5. B 6. D 7. A 8. D 9. A 10. A

SECTION- D

MCQ 1. C 2. B 3. A 4. A 5. C 6. C 7. D

8. D 9. C 10. C 11. A 12. C 13. B 14. D 15. C 16. B 17. B 18. B 19. B 20. B 21. A

22. D 23. A 24. A 25. C 26. C 27.B 28.A 29. C 30. D

**************************************************

72

Sample Question Paper (CBSE)

2021-22 Term-1 Subject:Chemistry(043)

Time:90 Minutes Max.Marks:35

GeneralInstructions:

1. The Question Paper contains three sections.

2. Section-A has 25 questions.Attempt any 20 questions.

3. Section-B has 24 questions. Attempt any 20 questions.

4. Section-C has 6 questions. Attempt any 5 questions.

5. All questions carry equal marks.

6. There is no negative marking.

***********************************************************************************************

SECTIONA

This section consists of 25 multiple choice questions with overall choice to attempt

any 20 questions. In case more than desirable number of questions are

attempted,ONLY first 20 will be considered for evaluation.

1. Which of the following statements is true:

(a)Melting point of Phosphorous is less than that of Nitrogen

(b)N2 is highly reactive while P4 is inert

(c)Nitrogen shows higher tendency of catenation than P

(d)N-N is weaker than P-P

2. Which of the following is a non-stoichiometric defect?

(a)Frenkel defect

(b)Schottky defect

(c)metal deficiency defect

(d)interstitial defect

3. Identify the law which is stated as:

―For any solution, the partial vapour pressure of each volatile component in the solution is

directly proportional to its molefraction.‖

(a) Henry‘slaw

(b) Raoult‘slaw

(c) Dalton‘slaw

(d)Gay-Lussac'sLaw

73

4. Pink colour of LiCl crystals is due to:

(a) Schottky defect

(b) Frenkel defect

(c) Metal excess defect

(d) Metal deficiency defect

5. Which of the following isomer has the highest melting point:

(a) 1,2-dicholorbenzene

(b) 1,3-dichlorobenzene

(c) 1,4-dicholorbenzene

(d) All isomers have same melting points

6. Which one of the following reactions is not explained by the open chain

Structure of glucose:

(a) Formation of pentaacetate of glucose with aceticanhydride.

(b) Formation of addition product with 2,4DNP reagent

(c) Silver mirror form at ion with Tollen‘s reagent

(d) Existence of alpha and beta forms of glucose.

7. Williamson‘s synthesis of preparing dimethylether is an:

(a) SN1reaction

(b) Elimination reaction

(c) SN2reaction

(d) Nucleophilic addition reaction

8. Chlorine water loses its yellow colour on standing because:

(a) HCl gas is produced,due to the action of sunlight.

(b) A mixture of HOCl and HCl is produced in the presence of light

(c) HOCl and hydrogen gas is produced

(d) A mixture of HCl and ClO3 is produced, due to the action of sunlight

9. During dehydration of alcohols to alkenes by heating with concentrated H2SO4,

the initiation step is:

(a) Protonation of alcohol molecule

(b) Formation of carbocation

(c) Elimination of water

(d) Formation of an ester

10. Amorphous solids are:

(a)Isotropic

(b) anisotropic

(c) isotopic

(d) isomeric 11. Which of the following reactions is used to prepare salicylaldehyde?

(a) Kolbe‘s reaction

(b) Etard reaction

(c) Reimer-Tiemann reaction

(d) Stephen‘s reduction.

74

12. Which of the following is an example of a solid solution?

(a) Sea water

(b) sugar solution

(c) Smoke

(d) 22 carat gold

13. The boiling points of alcohols are higher than those of hydrocarbons of comparable

masses due to:

(a)Hydrogen bonding

(b)Ion–dipole interaction

(c) Dipole-dipole interaction

(d) VanderWaal‘s forces.

14. Which of the following has the lowest boiling point:

(a) H2O

(b) H2S

(c) H2Se

(d) H2Te

15. Which of the following statement is correct:

(a)Fibrous proteins are generally soluble in water

(b)Albumin is an example of fibrous proteins

(c)In fibrous proteins, the structure is stabilized by hydrogen bonds and

disulphide bonds

(d)pH does not affect the primary structure of protein.

16. Major product obtained on reaction of 3-Phenylpropene with HBr in

presence of organic peroxide

(a) 3-Phenyl1-bromopropane

(b) 1–Phenyl-3-bromopropane

(c) 1-Phenyl-2-bromopropane

(d) 3-Phenyl-2-bromopropane

17. Which of the following is a correct statement for C2H5Br?

(a) It reacts with metallic Na to give ethane.

(b) It gives nitroethane on heating with aqueous solution of AgNO2

(c) It gives C2H5OH on boiling with alcoholic potash.

(d) It forms diethylthioether on heating with alcoholic KSH.

18. Covalency of nitrogen is restricted to:

(a) 2

(b) 3

(c) 4

(d) 5

75

19. Solubility of gases in liquids decreases with rise in temperature because dissolution is

an:

(a)endothermic and reversible process

(b)exothermic and reversible process

(c)endothermic and irreversible process

(d)exothermic and irreversible process

20. All elements of Group 15 show allotropy except:

(a) Nitrogen

(b) Arsenic

(c) Antimony

(d) Bismuth

21. Which of the following is a polysaccharide?

(a) Glucose

(b) Maltose

(c) Glycogen

(d) lactose

22. Substance having the lowest boiling point:

(a)Hydrogen

(b)Oxygen

(c)Nitrogen

(d)Helium

23. Lower molecular mass alcohols are:

(a) miscibleinlimitedamountofwater

(b) miscibleinexcessofwater

(c) miscibleinwaterinallproportions

(d) immiscibleinwater

24. Maximum oxidation state exhibited by Chlorine is:

(a)+1

(b) +3

(c)+5

(d)+7

25. In which of the following cases blood cells will shrink:

(a)when placed in water containing more than 0.9% (mass/volume) NaCl solution.

(b)when placed in water containing less than 0.9% (mass/volume) NaCl solution.

(c)when placed in water containing 0.9% (mass/volume) NaCl solution.

(d)when placed in distilled water.

SECTIONB

This section consists of 24 multiple choice questions with overall choice to

attempt any 20 questions. In case more than desirable number of questions

areattempted, ONLY first 20 will be considered for evaluation.

76

26. How much ethyl alcohol must be added to 1 litre of water so that the

solution will freeze at– 14°C?(Kf for water =1.86°C/mol)

(a) 7.5 mol

(b)8.5mol

(c)9.5mol

(d)10.5mol

27. Which reagents are required for one step conversion of chlorobenzene to toluene?

(a) CH3Cl/AlCl3

(b) CH3Cl,Na,Dry ether

(c)CH3Cl/Fe dark

(d) NaNO2/HCl/0-50C

28. On partial hydrolysis,XeF6 gives:

(a) XeO3+4HF

(b) XeO2F+HF

(c) XeOF4+H2

(d) XeO2F2+4HF

29. Which one of the following statement is correct about sucrose:

(a) It can reduce tollen‘s reagent however can not reduce fehling‘s reagent

(b) It undergoes mutarotation like glucose and fructose

(c) It undergoes inversion in the configuration on hydrolysis

(d) It is laevorotatory in nature. 30. Phenol does not undergo nucleophilic substitution reaction easily due to:

(a) Acidic nature of phenol

(b) Partial double bond character of C-OH bond

(c) Partial doublebond characterof C-C bond

(d) instability of phenoxide ion

31. Which of the following has highest ionisation enthalpy?

(a) Nitrogen

(b)Phosphorus

(c)Oxygen

(d)Sulphur

32. Metal M ions form a ccp structure. Oxide ions occupy ½ octahedral and

½ tetrahedral voids. What is the formula of the oxide?

(a) MO

(b) MO2

(c) MO3

(d) M2O3

33. The reaction of toluene with Cl2 in presence of FeCl3 gives ‗X‘ while the

of toluene with Cl2 in presence of light gives‗Y‘. Thus ‗X‘ and ‗Y‘ are:

(a) X=benzylchloride Y=o and p–chlorotoluene

(b) X=m–chlorotoluene Y=p–chlorotoluene

(c) X=o and p–chlorotoluene Y=trichloromethylbenzene

(d) X=benzylchloride, Y=m-chlorotoluene

77

34. Ozone is a/an molecule and the two O-O bond lengths in ozone

are(i) - and (ii)

(a) linear,110pm;148pm

(b) angular,110pm ; 148 pm (c)

linear, 128pm;128pm

(d) angular,128pm;128pm

35. Water retention or puffiness due to high salt in take occurs due to:

(a)diffusion

(b) vapourpressuredifference

(c) osmosis

(d) (d)reverseosmosis

36. In the following reaction, identify A and B:

C6H12O6 Aceticanhydride A

Conc.nitricacid

B

(a) A=COOH-(CH2)4-COOH, B= OHC-(CHOCOCH3)4-CH2OCOCH3

(b) A=COOH-(CH2)4-CHO , B= OHC-(CHOCOCH3)4-CH2OCOCH3

(c) A=OHC-(CHOCOCH3)3-CH2OCOCH3B=COOH-(CH2)4-CHO,

(d) A=OHC-(CHOCOCH3)4-CH2OCOCH3B=COOH-(CH2)4-COOH

37. In lake test for Al3+ ions, there is the formation of coloured ‗floatinglake‘ . It

is due to:

(a)Absorption of litmus by [Al(OH)4]-

(b)Absorption of litmus by Al(OH)3

(c) Adsorption of litmus by [Al(OH)4]-

(d)Adsorption of litmus by Al(OH)3

38. A unit cell of NaCl has 4 formula units. Its edgelength is 0.50 nm. Calculate

the density if molar massof NaCl=58.5g/mol.

(a)1g/cm3

(b)2g/cm3

(c)3g/cm3

(d)4g/cm3

39. Which one of the following are correctly arranged on the basis of the property indicated:

(a) I2<Br2<F2<Cl2[increasing bond dissociation enthalpy] (b) H2O>H2S<H2Te<H2Se [increasing acidic strength] (c) NH3<N2O<NH2OH<N2O5 [increasing oxidation state] (d) BiH3<SbH3<AsH3<PH3<NH3[increasing bond angle]+

78

40. What would be the reactant and reagent used to obtain 2,4-dimethylpentan-3-

ol?

(a) Propanal and propylmagnesiumbromide

(b) 3-methylbutanal and 2-methylmagnesiumiodide

(c) 2-dimethylpropanone and methylmagnesiumiodide

(d) 2-methylpropanal and isopropylmagnesiumiodide

41. o-hydroxybenzyl alcohol when reacted with PCl3 gives the productas (IUPACname)

(a) o-hydroxybenzylchloride

(b) 2-chloromethylphenol

(c) o-chloromethylchlorobenzene

(d) 4-hydroxymethylphenol

42. Which of the following statements is true:

(a) Ammonia is the weakest reducing agent and the strongest base among

Group15 hydrides.

(b) Ammonia is the strongest reducing agent as well as the strongest base

among Group15 hydrides.

(c) Ammonia is the weakest reducing agent as well as the weakest base

among Group 15 hydrides.

(d) Ammonia is the strongest reducing agent and the weakest base among Group 15 hydrides.

43. Identify the secondary alcohols from the following set: (i)CH3CH2CH(OH)CH3

(ii)(C2H5)3COH

(iii)

(iv)

(a)(i) and (iv)

(b)(i) and (iii)

(c)(i) and (ii)

(d)(i), (iii) and (iv)

44. Alkenes decolourise bromine water in presence of CCl4 due to formation of:

(a)allylbromide

(b)vinylbromide

(c)bromoform

(d)vicinaldibromide

79

45. Given below are two statements labeled as Assertion (A) and Reason(R)

Assertion(A): Electron gain enthalpy of oxygen is less than that of Flourine but

greater than Nitrogen.

Reason(R): Ionisation enthalpies of the elements follow the order

Nitrogen>Oxygen>Fluorine

Select the most appropriate answer from the options given below:

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not the correct explanation o fA.

(c) A is true but R is false.

(d) A is false but R is true.

46. Given below are two statements labeled as Assertion(A) and Reason(R)

Assertion(A):Alkyl halides are in soluble in water.

Reason(R):Alkyl halides have halogen attached to sp3 hybrid carbon.







Assertion(A): Molarity of a solution changes with temperature.

Reason(R):Molarity is a colligativeproperty.






48. Given below are two statements labeled as Assertion(A) and Reason(R) Assertion(A):SO2 is reducing while TeO2 is an oxidising agent.

Reason(R):Reducing property of dioxide decreases from SO2 to TeO2.







Assertion(A):Cryoscopic constant depends on nature of solvent.

Reason(R):Cryoscopic constant is a universal constant.

Selectthemostappropriateanswerfromtheoptionsgivenbelow:






80

SECTIONC This section consists of 6 multiple choice questions with an overall choice to

attempt any 5. In case more than desirable number of questions are attempted,

ONLY first 5 will be considered for evaluation.

50. Matchthefollowing:

I II

(i)Aminoacids (A)protein

(ii)Thymine (B)Nucleicacid

(iii)Insulin (C)DNA

(iv)phosphodiesterlinkage (D)Zwitterion

(v)Uracil

Which of the following is the best matched options?

(a) i-A,v-D,iii-C,iv-B

(b) i-D,ii-C,iii-A,iv-B

(c) i-D,v-D,iii-A,iv-B

(d) i-A,ii-C,iii-D,iv-B

51. Which of the following analogies is correct:

(a) Nitrogen:1s22s22p3::Argon:1s22s22p6

(b) Carbon:maximum compounds::Xenon:no compounds

(c) XeF2:Linear::ClF3:Trigonal planar

(d) Helium:meteorological observations :: Argon:metallurgical processes

52. Complete the following analogy:

Same molecular formula but different structures : A :: Non super imposable mirror

images : B

(a) A:Isomers B:Enantiomer

(b)A:Enantiomers B:Racemic mixture

(c) A:Sterio isomers B:Retention

(d)A:Isomers B:Sterioisomers

CASE1: Read the passage given below and answer the following questions

53-55

Early crystallographers had trouble solving the structures of inorganic solids using X-

ray diffraction because some of the mathematical tools for analyzing the data had not

yet been developed. Once at rial structure was proposed, it was relatively easy to

calculate the diffraction pattern, but it was difficult to go the other way (from the

diffraction pattern to the structure) if nothing was known apriori about the

arrangement of atoms in the unit cell. It was important to develop some guidelines for

guessing the coordination numbers and bonding geometries of atoms in crystals. The

first such rules were proposed by Linus Pauling, who considered how one might pack

together oppositely charged spheres of different radii.

Pauling proposed from geometric considerations that the quality of the "fit" depended

on the radius ratio of the anion and the cation.

81

If the anion is considered as the packing atom in the crystal, then the smaller

cation fills interstitialsites ("holes"). Cations will find arrangements in which they

can contact the largest number of anions. If the cation can touch all of its

nearest neighbour anions then the fit is good. If the cation is too small for a

given site, that coordination number will be unstable and it will prefer a lower

coordination structure. The table below gives the ranges of cation/anion radius

ratios that give the best fit for a given coordination geometry.

Coordination

number Geometry ρ=rcation / ranion

2 linear 0-0.155 3 triangular 0.155-0.225

4 tetrahedral 0.225-0.414

4 squareplanar 0.414-0.732 6 octahedral 0.414-0.732

8 cubic 0.732-1.0 12 cuboctahedral 1.0

(Source: Ionic Radii and Radius Ratios. (2021,June8). Retrieved June29,2021, from

https://chem.libretexts.org/@go/page/183346)

Q53.The radius of Ag+ ion is 126 pm and of I-ion is 216 pm. The coordination number

of Ag+ion is:

(a) 2

(b) 3

(c) 6

(d) 8

Q54. A solid AB has square planar structure. If the radius of cation A+ is 120 pm, calculate the maximum possible value of anion B-

(a)240pm

(b)270pm

(c)280pm

(d)290pm

Q55. A ―good fit‖ is considered to be one where the cation can touch:

(a) All of its nearest neighbour anions.

(b) Most of its nearest neighbour anions.

(c) Some of its nearest neighbour anions.

(d) None of its nearest neighbour anions.

https://chem.libretexts.org/%40go/page/183346)

82

CHEMISTRY(043) MarkingScheme

SECTIONA

1.(d)N-N is weaker than P-P

other statements as incorrect as Phosphorus has a higher melting point due to

bigger size than Nitrogen.Nitrogen is inert due to formation of triple bonds and

has a lower covalence due to non- availability of d –orbitals

2. (c)metal deficiency defect (anion is missing from latticesite)

In Frenkel defect the smaller ion occupies the interstitial sites and Schottky defect equal numberof cations and anions are missing. Interstitial defect an atom or molecule occupies intestinal sites so in these three defects the ratio of positive and

negative ions (Stoichiometric) of a solid is not disturbed in these three

3. (b)Raoult‘slaw

4. (c)Metal excess defect (formation of F-centres)

5. (c)1,4-dicholorbenzene(para isomers are more symmetric than ortho and meta)

6. (d) existence of alpha and beta forms of glucose.

7. (c)S2 reaction(alkoxide ion reacts with primary alkyl halide in a single step to form ether )

8. (b) a mixture of HOCl and HCl is produced in the presence of

sunlight Cl2(g)+H2O(l) → HCl (g) +HOCl(aq)

9. (a)protonation of alcohol molecule

10. Amorphous solids are:

(a) isotropic (the value of any physical property is same along any direction)

11. (c) Reimer- Tiemann reaction( Kolbe‘s reaction is used to prepare salicylic acid, Etard reaction for benzaldehyde, Reimer- Tiemann reaction for

salicylaldehyde and Stephen‘s reduction for aldehyde)

83

12. (d)22 carat gold (it is an alloy so solid in solid solution)

13. (a)Hydrogen bonding (alcohols form intermolecular hydrogenbonds)

14. (b)H2S(boilingpointincreasesdownthegroupbutwaterformsstronghydrogenbond

ssohashigher boiling pointthan H2S)

15. (d)pHdoesnotaffecttheprimarystructureofprotein(pHeffectsthetertiarystructure)

16. (b)1–Phenyl-3-bromopropane ((C6H5)CH2CH=CH2 + HBr (organic peroxide) → (C6H5)CH2CH2CH2Br

anti-Markovnikov addition)

17. (b)It gives nitroethane on heating with aqueous solution of AgNO2

18. (c) 4 (Covalency of nitrogen is restricted to 4 due to non availability of d orbitals)

19. (b)exothermic and reversible process (according to Le -Chatlier principle Solubility of gases in liquids decreases with rise in temperature)

20. (a)Nitrogen (due to small size and high electronegativity N-N is weak)

21. (c) glycogen(It is a polymer of glucose)

22.(d)Helium (He is monoatomic and has low atomic mass)

23.(c) miscible in water in all proportions Lower molecular mass alcohols are

able to form hydrogen bonds with water 24.(d)+7(Cl:1s22s22p63s23p5)

25.(a)When placed in water containing more than 0.9% (mass/ volume) NaCl solution because fluid inside blood cells is isotonic with 0.9% NaCl solution

84

SECTIONB

26.(a) 7.5mol

ΔTf=Kfm

ΔTf= Kfn2x 1000

w1 14= 1.86 x n2x 1000

1000

n2=7.5 mol

27. (b)CH3Cl,Na,Dry ether

28. (d)XeO2F2+4HF

XeF4+H2O→XeO2F2+4HF

29. (c)It undergoes inversion in the configuration on hydrolysis 30. (b)partial double bond character of C-OH bond 31. (a)Nitrogen (High IE of N is because of smallest size in the group and completely

half – filled p sub-shell) 32.(d)M2O3

33. c)X=o and p– chlorotoluene, Y=trichloromethylbenzene

34. (d)angular,128pm;128pm(Ozone is a resonance hybrid of two equivalent structures)

35. (c)Osmosis

36. d)A=OHC-(CHOCOCH3)4-CH2OCOCH3 B=COOH-(CH2)4-COOH

37. (d)Adsorption of litmus by Al(OH)3

38.(c)3g/cm3 39. (d) BiH3<SbH3<AsH3<PH3<NH3[increasing bond angle]correct order 40. (d)2-methylpropanal and isopropylmagnesiumiodide

85

41. (b)2-chloromethylphenol

42. (a)Ammonia is the weakest reducing agent and the strongest base among

Group 15 hydrides.The reducing character of hydrides increases down the group

due to decrease in bond dissociation enthalpy.

43 (a)(i) and (iv)

(i)CH3CH2CH(OH)CH3(secondary)(ii)(C2H5)3COH(tertiary)

(iii) (iv)

Phenolnotan alcohol secondary

44.(d)vicinaldibromide

CH2=CH2+Br2→BrCH2-CH2Br

45. (c) Assertion: Electron gain enthalpy of oxygen is less than that of Flourine but

greater than Nitrogen.(correct)

Reason: Ionisation enthalpies of the elements follow the order Nitrogen >Oxygen > Fluorine (incorrect)

Ionisation enthalpies of the elements follow the order Fluorine>Nitrogen>Oxygen

46. (b)Assertion:Alkylhalides are insoluble in water.(correct)

Reason:Alkyl halides have halogen attached to sp3 hybrid carbon.(correct)

Alkyl halides are insoluble in water because they are unable to form hydrogen bonds with water or break pre-existing hydrogen bonds.

47. (c)Assertion: Molarity of a solution changes with temperature. (correct)

Reason:Molarity is a colligative property.(incorrect) Molarity is a means to express concentration. It is not a physical property.

48. (a)Assertion:SO2 is reducing while TeO2 is an oxidising agent.(correct)

Reason:Reducing property of dioxide decreases from SO2to TeO2 (correct and

reason for Assertion)

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49. (c)Assertion:Cryoscopic constant depends on nature of solvent.(correct)

Reason: Cryoscopic constant is a universal constant (incorrect)

Cryoscopic constant various with type of solvent

SECTIONC

50. (b)i-D,ii-C,iii-A,iv-B Amino acids form proteins and exist as zwitter ion , Thymine is a nitrogenous base

in DNA,Insulin is a protein, phosphodiester linkage is found in nucleic acids so also

in DNA and Uracil is nitrogenous base found in RNA which is a nucleic acid.

51. (d)Helium: meteorological observations :: Argon: metallurgical processes Nitrogen: 1s22s22p3:: Argon:1s22s22p6 is configuration of Neon not Argon Carbon:

maximum compounds :: Xenon : no compounds, Xenon forms compounds XeF2:

Linear :: ClF3: Trigonalplanar,ClF3is T-shaped not Trigonal planar

52. (a)A:Isomers B: Enantiomer Isomers have Same molecular formula but different

structure Enantiomers are Non superimposable mirror images Q53.(c)6

The radius of Ag+ ion is 126 pm and of I- ion is 216 pm.The coordination number of

Ag+ ion is:

ρ=rcation/ranion= 126/216=0.58

Radius ratio lies in the range 0.414 – 0.732, so has coordination number 6 or 4

according to the table.

Since none of the options is 4,so the answer is 6

Q54. (d)290 pm

Square planar means ratio ratio is between 0.414–0.732

If radius of cation is 120 pm then anion should be in the range ρ

= rcation/ranion 0.414 = 120/x so x = 289.8 = 290 pm

0.732 = 120/x so x = 163.9 = 164 pm

Q55.(a)all of its nearest neighbour anions

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PRACTICE QUESTION PAPER Term 1 Subject: Chemistry (043)

Time: 90 Minutes Max. Marks: 35

General Instructions: 1. The Question Paper contains three sections.

2. Section A has 25 questions. Attempt any 20 questions. 3. Section B has 24 questions. Attempt any 20 questions. 4. Section C has 6 questions. Attempt any 5 questions.

5. All questions carry equal marks. 6. There is no negative marking.

SECTION A This section consists of 25multiple choice questions with overall choice to attempt

any 20 questions. In case more than desirable number of questions are attempted, ONLY first 20 will be considered for evaluation.

1 XeF2 is iso structural with: A. BaCl2 B. ICl2-

C. TeF2 D. SbCl3

2 A substance Ax By, CRYSTALLISES IN A fcc lattice in which atoms A occupy each corner of the cube & atoms B occupy the centres of each face of the cube.

Identify the correct composition of the substance Ax By. A.AB3 B. A4B3

C.A3B

3 Which of the following is unit less?

A. Molality B. Molarity

C. Mole fraction D. Mass percentage

4 The correct statement regarding defects in solids is

A. Frenkel defect is favoured by small difference in the sizes of cation & anion. B. Frenkel defect is a non-stoichiometric defect.

C. Trapping of electron in the lattice lead to formation of F-centre. D. Schottky defect has no effect on the physical property of solids.

The one extensive use of piezoelectric material is

5 Identify the following compounds as primary halide:

A. 1-Bromobut-2-ene B. 4-Bromopent-2-ene C. 2-Bromo-2-methylpropane

D.t-butyl bromide

6 Which of the following is not a monosaccharide?

A. Glucose B. Fructose

C. Cellulose D. Ribose

7 Tertiary alkyl halides are practically inert to substitution by SN2

mechanism because of A. insolubility

B. instability C. inductive effect

D. steric hindrance

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8 A greenish yellow gas with pungent smell which when dissolved in water forms a bleaching agent is- A. Cl2

B. F2 C. Br2

D. I2

9 Which of the following compounds will give butanone on oxidation with alkaline

KMnO4 solution? A. Butan-1-ol B. Butan-2-ol

C. Both of these D. None of these

10 Metal M exist as M+2 & M+3 in its oxide (M0.98O). fraction of metal in M+3 form is A. 4.08%

B. 6.05% C. 5.08% D. 7.01%

11 Which of the following reactions is used to prepare salicylaldehyde? A. Kolbe‘s reaction

B. Etard reaction C. Reimer- Tiemann reaction

D. Stephen‘s reduction.

12 To avoid bends, the tanks used by scuba divers are filled with air diuted with A. Helium gas

B. Argon gas C. Krypton gas

D. None of the above

13 The boiling points of alcohols are higher than those of hydrocarbons of

comparable masses due to: A. Hydrogen bonding

B. Ion – dipole interaction C. Dipole- dipole interaction

D. Van der Waal‘s forces.

14 Sulphur shows paramagnetic behaviour in which state A. S8

B. S2 C. S6 D. S4

15 Peptide upon hydrolysis gives –

A. Amine B. Amino acid

C. Ammonia D. Amide

16 C-Cl bond in chlorobenzene in comparison to C-Cl bond in in methyl chloride is

A. Longer & weaker B. Shorter & weaker

C. Shorter & stronger D. Longer & stronger

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17 The synthesis of alkyl fluoride is best accomplished by – A. Finkelstein reaction B. Swartz reaction

C. Free radical fluorination D. Sandmeyer‘s reaction

18 Which of the following elements does not show allotropy? A. nitrogen

B. bismuth C. antimony D. arsenic

19 Value of Henry‘s constant KH A. increases with increase in temperature

B. decreases with increase in temperature C. remains constant

D. ) first increases, then decreases

20 Conc. HNO3 turn brown, on standing due to formation of A.NO

B.NO2 C.N2O

D.N2O4

21 Name the linkage that holds the two units in the disaccharide ?

A. Nucleoside linkage B. Glycosidic linkage C. Peptide linkage

D. None of the above

22 Which is the incorrect statement?

A. O3 is a allotrope of oxygen. B. O3 is pale blue gas.

C. O3 protects us from IR rays of sun. D. O3 depletion is due to CFCs.

23 The compound which does not undergo hydrolysis by SN1 mechanism is A. CH2=CHCH2Cl B. C6H5Cl

C. C6H5CH2Cl D. C6H5CH (CH3) Cl

24 Which of the following does not exist? A. XeO3

B. XeOF4 C.XeF6 D.NeF2

25 An unripe mango placed in a concentrated salt solution to prepare pickles shrivels because

A. it gains water due to osmosis

B. it loses water due to reverse osmosis C. it gains water due to reverse osmosis D. it loses water due to osmosis

SECTION B This section consists of 24multiple choice questions with overall choice

to attempt any 20questions. In case more than desirable number of questions are attempted, ONLY first 20 will be considered for evaluation.

90

26 If 2 gm of NaOH is present is 200 ml of its solution, its molarity will be A. 0.025 B. 0.5

C. 5 D. None of the above

27 Which of the following is the correct order of decreasing SN2 reactivity?

(A) RCH2X > R2CHX > R3CX (B) R3CX > R2CHX >RCH2X (C) R2CHX >R3CX > RCH2X

(D) RCH2X >R3CX >R2CHX

28 Which group 16 element is the most electronegative? A. Sulphur

B. Polonium C. Oxygen D. Selenium

29 Glucose on reaction with acetic acid gives glucose pentaacetate. What does it

suggest about the structure of glucose ? A. C-1 is anomeric carbon

B. C-5 is anomeric carbon C. 3 -OH groups are present D. 5 -OH groups are present

30 The alcohol which does not react with Lucas reagent is –

A. isobutyl alcohol B. n-butanol

C. tert-butyl alcohol D. sec-butyl alcohol

31 What is the correct order of enthalpy of dissociation of halogens? A . F2 > Cl2 > Br2 > I2

B.Cl2> Br2 >F2 >I2 C. Cl2 > F2 > Br2 > I2

D. F2 > Br2 > Cl2 > I2

32 Which of the following is not a crystalline solid? A. KCl B. CsCl

C. Glass D. Rhombic S

33 Which of the following compounds will form when Bromo ethane reacts with Mg

in presence of dry ether

A CH3-CH3

B CH3-CH2MgBr

C CH3MgBr

D(CH3)2MgBr

91

34 When XeF6 is partially hydrolysed, it yields

A. XeSO3

B. XeOF2

C. XeOF4

D. XeF2

35 The osmotic pressure is expressed in the units of- A. MeV

B. Calories C. atmosphere D. cm/sec

36 Proteins are found to have two different types of secondary structures, viz. a-helix and b-pleated sheet structure. a-helix structure of protein is stabilised by

A. Peptide bonds B. van der Waals forces C. Hydrogen bonds

D. Dipole-dipole interactions

37 Which of the following bases is not present in DNA? A. Adenine

B. Thymine C. Cytosine D. Uracil

38 The packing efficiency of a metal crystal for simple cubic lattice is

A. 52.4%

B. 65%

C. 60%

D. 54.5%

39 The shape of XeF4 is

A. tetrahedral

B. square planar

C. pyramidal

D. linear

40 Phenol reacts with Br2 in CS2 at low temperature to give – A. o-Bromophenol

B. o-and p-Bromophenols C. p-Bromophenol

D.2, 4, 6 –Tribromophenol

92

41 Acetone reacts with Grignard reagent to form – A. 3° alcohol

B 2° alcohol C Ether

D No reaction

42 Which of the following halogen exists as a solid at room temperature? A.Chlorine B. Fluorine

C. Iodine D. Bromine

43 The compound which gives the most stable carbonium ion on dehydration is –

A. (CH3)2CHCH2OH B. (CH3)3COH C. CH3CH2CH2CH2OH

D. CH3CH OH CH2 CH3

44 A primary alkyl halide would prefer to undergo _____________.

A. SN1 reaction

B. SN2 reaction C. α–Elimination

D. Racemisation

Directions: These questions consist of two statements, each printed as

Assertion and Reason. While answering these questions, you are required to choose any one of the following four responses. (a) If both Assertion and Reason are correct and the Reason is a correct

explanation of the Assertion. (b) If both Assertion and Reason are correct but Reason is not a correct

explanation of the Assertion. (c) If the Assertion is correct but Reason is incorrect. (d) If both the Assertion and Reason are incorrect.

45 Assertion:-N2 is less reactive than P4

Reason:-Nitrogen has more electron gain enthalpy than phosphorus.

46

Assertion: It is difficult to replace chlorine by –OH i chlorobenzene in comparison to that in chloroethane.

Reason: C-Cl bond in chlorobenzene has a partial double bond character due to resonance.

47 Assertion : Molarity of a solution in liquid state change with temperature.

Reason: The volume of the solution changes with change in temperature.

48 Assertion: XeF2 has linear geometry Reason:-The molecule has two lone pair of electron.

93

49 Assertion : Osmotic pressure of 0.1 M urea solution is less than that of 0.01 M NaCl solution.

Reason: Osmotic pressure is not a colligative property.

SECTION C This section consists of 6multiple choice questions with an overall choice

attempt any 5. In case more than desirable number of questions are attempted, ONLY first 5 will be considered for evaluation.

50 Proteins can be classified into two types on the basis of their molecular shape i.e., fibrous proteins and globular proteins. Examples of globular proteins are :

(i) Insulin (ii) Keratin (iii) Albumin (iv) Myosin A.(i) and (iii)

B.(ii) and (iii) C.(ii) and (iv)

D.(i) and (iv)

51 Out of (i) XeO3 (ii) XeOF4 and (iii) XeF6 , the molecules having the samenumber

of lone pairs on Xe are

A.(i) and (ii) only B.(i) and (iii) only

C.(ii) and (iii) only D(i) , (ii) and (iii)

52 Which reagent will you use for the following reaction ?

A. Cl2/UV light B. NaCl + H2SO4

C. Cl2 gas in dark D. Cl2 gas in the presence of iron in dark

CASE 1 Read the passage given below and answer the following questions 53-55

An ideally perfect crystal is one which has the same unit cell and contains the

same lattice points throughout the crystal. The term imperfection or defect is

generally used to describe any deviation of the ideally perfect crystal from the

periodic arrangement of its constituents.

If the deviation occurs because of missing atoms, displaced atoms or extra

atoms, the imperfection is named as a point defect.

Such defects can be the result of imperfect packing during the original

crystallisation or they may arise from thermal vibrations of atoms at elevated

temperatures because with increase in thermal energy there is increased

probability of individual atoms jumping out of their positions of lowest energy.

Type of point defects – point defects in a crystal may be classified into three

types

94

1.Stoichiometric defects

2.Non – stoichiometry defects

3. Impurity defects

53 Which of the following defects is not a type of Stoichiometry defects ?

A. Vacancy defect

B. Interstitial Defect

C. Schottky defect

D. Metal excess defect

54 In which of the following defects equal number of anions and cations are missing

from

lattice site?

A. Vacancy defect

B. Interstitial defect

C. Schottky defect

D. Frenkel Defect

55 Which of the following compounds does not show metal deficiency defect?

A. FeO

B. FeS

C. NiO

D. NaCl

95

ANSWER KEY

SECTION A SECTION B SECTION C

Q. No Correct Option Q. No Correct Option Q. No Correct Option

1 B 26 A 51 D

2 A 27 A 52 A

3 C 28 C 53 D

4 C 29 D 54 C

5 A 30 B 55 D

6 C 31 B

7 D 32 C

8 A 33 B

9 B 34 C

10 A 35 C

11 C 36 C

12 A 37 D

13 A 38 A

14 B 39 B

15 B 40 B

16 C 41 A

17 B 42 C

18 A 43 B

19 A 44 A

20 B 45 C

21 B 46 A

22 C 47 A

23 C 48 C

24 D 49 C

25 D 50 A

subject-chemistry term-1 session 2021-22

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