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S.NO Questions Answers 1 What is the IUPAC name of the complex [Ni(NH3)6]Cl2 ? Ans.1

Hexaamninenickel (II) chloride 2 Draw the structure of 3-methylpentanal.

Ans.2

3 Complete the following reaction equation :

C6H5N2Cl + H3PO2 + H2O ––––→ - - -

Ans.3 C6H5N2Cl + H3PO2 + H2O ––––→ C6H6 + H3PO3 + N2 +HCl

4 Explain the mechanism of dehydration steps of ethanol :- H+

1. CH3CH2OH → CH2 = CH2 + H2O 443 K

Ans.4

5 Define osmotic pressure of a solution. How is the osmotic pressure related to the concentration of a solute in a solution ?

Ans.5 Osmotic pressure is the minimum pressure which needs to be applied to a solution to prevent the inward flow of water across a semi permeable membrane. It is also defined as the measure of the tendency of a solution to take in water by osmosis. The osmotic pressure is directly proportional to concentration of the solution. /= CRT

6 What is the no. of atoms per unit cell (z) in a body-centred cubic structure ?

Ans.6 2

7 In reference to surface chemistry, define dialysis. Ans.7 The separation of crystalloids from colloids in asolution by diffusion through a membrane8 Define the following terms :

Half-life of a reaction (t½) Rate constant (k)

Ans.8 . i) The half-life of a reaction, t1/2, is the amount of time needed for a reactant concentration to decrease by half compared to its initial concentration. ii) A coefficient of proportionality relating the rate of a chemical reaction at a given temperature to

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the concentration of reactant (in a unimolecular reaction) or to the product of the concentrations of reactants.

9 Draw the structures of the following : i) H2SO4 ii) XeF2

Ans.i)

ii)

10 What is meant by ‘disproportionation’ ? Give an example of a

disproportionation reaction in aqueous solution. OR

Suggest reasons for the following features of transition metal chemistry : i) The transition metals and their compounds are usually paramagnetic. ii) The transition metals exhibit variable oxidation states.

Ans.10 A reaction in which a substance is simultaneously oxidized and reduced, giving two different products.

Ans : (i) Paramagnetism in the transition elements is caused by the presence of unpaired electrons in the d orbitals. Diamagnetism is characteristic of compounds where all the electrons are paired in the d orbitals. ii) The transition metals exhibit variable oxidation states due to incomplete filling of d-orbitals.

11 How are the following conversions carried out ? (i)Propene to propane-2-ol (ii)Benzyl chloride to Benzyl alcohol (iii) Anisole to p-Bromoanisole

Ans.11 i)

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ii)

iii)

12 An aromatic compound ‘A’ on treatment with aqueous ammonia and heating forms compound ‘B’ which on heating with Br2 and KOH forms a compound ‘C’ of molecular formula C6H7N. Write the structures and IUPAC names of compounds A, B

Ans.12 (A)Benzoic acid-C6H5OH (B)Benzamide-C6H5CONH2 (C)Aniline-C6H5NH2

13 How are vitamins classified ? Name the vitamin responsible for the coagulation of blood.

Ans.13 Fat-soluble Vitamins – Vitamin A, K, E , D Water-soluble Vitamins- Vitamin C, B, Biotin Vitamin K is a group of structurally similar, fat-soluble vitamins the human body requires for complete synthesis of certain proteins that are prerequisites for blood coagulation that the body needs for controlling binding of calcium in bones and other tissues.

14 Write the names and structures of the monomers of the following polymers : i) Buna-S ii) Neoprene iii) Teflon

Ans.14

(ii)Neoprene

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iii) Teflon

15 Define the following :

i) Schottky defect ii) Frenkel defect iii) F-centre

Ans.15 (i) A Schottky defect- is a type of point defect in a crystal lattice named after Walter H. Schottky. In non-ionic crystals it means a lattice vacancy defect. In ionic crystals, the defect forms when oppositely charged ions leave their lattice sites, creating vacancies. (ii)Frenkel defect : The Frenkel Defect (also known as the Frenkel pair/disorder) is a defect in the lattice crystal where an atom or ion occupies a normally vacant site other than its own. As a result the atom or ion leaves its own lattice site vacant (iii)F-centre : An F-center, is a type of crystallographic defect in which an anionic vacancy in a crystal is filled by one or more unpaired electrons.

16 45 g of ethylene glycol (C2H4O2) is mixed with 600 g of water. Calculate the freezing point depression and the freezing point of the solution (Given : Kf of water = 1.86 K kg mol–1)

Ans.16

17 The rate constants of a reaction at 500 K and 700 K are 0.02 s–1

and 0.07 s–1 respectively. Calculate the value of activation energy, Ea. (R = 8.314 J K–1 mol–1)

Ans.17 log K2/K1= Ea/ 2.303R [T2-T1/T1T2] Log .07/.02 = Ea/2.303*8.314 JK-1mol-1[700 -500/700*500] 0.544=Ea * 5.17* 104/ 19.5

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Ea = .544* 19.5/ 5.17 *104 = 18230.8 J 18 Define the following terms :

i) Electrophoresis ii) Adsorption iii) Shape selective catalysis

Ans.18 (i) Electrophoresis: is the motion of dispersed particles relative to a fluid under the influence of a spatially uniform electric field. (ii)Adsorption : Adsorption is the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface. This process creates a film of the adsorbate on the surface of the adsorbent. (iii)Shape selective catalysis : The catalytic reaction that depends upon the structure of pores of the catalyst and the size of the reactant and product molecules is called shape/selective catalysis

19 Outline the principles of refining of metals by the following methods : i) Distillation ii) Zone refining iii) Electrolysis

OR Write down the reactions taking place in different zones in the blast furnace during the extraction of iron. How is pig iron different from cast iron ?

Ans.19 i) The impure metal is evaporated to obtain the pure metal as distilliate is known as distillation. ii) This method is based on the principle that the impurities are more soluble in the melt than in the solid state of the metal. iii)The impure metal is made to act as anode.A strip of the same metal in pure form is used as cathode. They are put in suitable electrolytic bath containing soluble salt of the same metal the more basic metal remains in the solution and in the less basic one go to the anode mud.

OR Cast iron has lower carbon content (about3%) than pig iron/cast iron is hard & brittle whereas pig iron is soft.

20 What is lanthanoid contraction ? What are the consequences of

lanthanoid contraction?

Ans.20 The shielding effect of 4f electrons from the increased nuclear charge is poor. Thus, as the atomic number increases, the effective nuclear charge experienced by each 4f electron increases. This causes a slight reduction in the entire 4f shell. The successive contractions accumulate and the total effect for all the lanthanides is called lanthanoid (or lanthanide) contraction. Consequence of Lanthanide Contraction:

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Separation of Lanthanides Basic Strength of Hydroxide Similarity of second and third transition series

21 Indicate the types of isomerism exhibited by the following complexes :

(i) [Co(NH3)5(NO2)]2+

(ii) [Co(en)3]Cl3 (en = ethylene diamine)

(iii) [Pt(NH3)2Cl2]

Ans.21 Linkage isomerism-[Co(NH3)5(NO2)]2+ Optical isomerism-[Co(en)3]Cl3 (en = ethylene diamine) Cis - trans / Geometrical isomerism-[Pt(NH3)2Cl2]

22 Name the following according to IUPAC system :

Ans.22

i) Butan – 2 – ol

ii) 2 – bromotoluene iii) 2, 2-dimethylchlorpropane

23 Ramesh went to a departmental store to purchase groceries. On one of shelves he noticed sugar-free tablets. He decided to buy them for his grandfather who was a diabetic. There were three types of sugar-free tablets. Ramesh decided to buy sucrolose which was good for his grandfather’s health. Name another sugar free tablet which Ramesh did not buy. i) Was it right to purchase such medicines without doctor’s prescription ? ii) What quality of Ramesh is reflected above ?

Ans.23 i) Aspartame, Saccharin ii) No iii) Social concern, empathy, concern, social awareness ,knowledge

24 (a)Describe the following giving chemical equations : Ans.24

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(i)De-carboxylation reaction ii) Friedel-Crafts reaction b)How will you bring about the following conversions ? i) Benzoic acid to Benzaldehyde ii) Benzene to m-Nitroacetophenone iii) Ethanol to 3-Hydroxybutanal

OR Describe the following actions : (i)Acetylation (ii) Aldol condensation b) Write the main product in the following equations :

i) De-carboxylation reaction The Friedel–Crafts reactions are a set ofreactions developed by Charles Friedel and James Crafts1877 to attach substituents to an aromatic ring. There are two main types ofFriedel–Crafts reactions: alkylation reactions and acylation reactions. Both proceed by electrophilic aromatic substitution.

(b) (i)Benzoic acid to Benzaldehyde :

(ii)Benzene to m-Nitroacetophenone :

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(iii)Ethanol to 3-Hydroxybutanal :

OR

(a) Acetylation :Acylation is the process of adding an acyl group to a compound. The compound providing the acyl group is called the acylating agent. Aldol condensation:An aldol condensation is an organic reaction in which an enol or an enolate ion reacts with a carbonyl compound to form a β-hydroxyaldehyde or β-hydroxyketone, followed by a dehydration to give a conjugated enone.Aldol condensations are important in organic synthesis, providing a good way to form carbon–carbon bonds.

(b) LiAlH4 (i)CH3 – C – CH3 ––––––––––––– CH3 – C – CH3 (2- propanol) | | | O OH

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PCl5 iii) CH3 – COOH –––––––––––––→ CH3COl (Acetyl chloride)

25 .a)Complete the following chemical reaction equations : i) Cu + HNO3(dilute) → ii) P4 + NaOH+ H2O → (i) Why does R3P = O exist but R3N = O does not ? (R = alkyl group) i) Why is dioxygen a gas but sulphur a solid ? ii) Why are halogens coloured ?

OR Write balanced equations for the following reactions : i) Chlorine reacts with dry slaked lime. ii) Carbon reacts with concentrated H2SO4. b) Describe the contact process for the manufacture of sulphuric acid with special reference to the reaction conditions, catalysts used and the yield in the process.

Ans.25 a) (i)

ii) (b) (i) N doesn not have d orbitals.Therfore it cannot form p Π - d Π bonds.Therefore N cannot expand its covalency beyond four.In R3N =O , N has a covalency equal to five, therefore R3N =O cannot exist. P has d orbitals , therefore forms p Π - d Π multiple bonds and therefore can expand its covalency beyond four.Therfore R3P= O exists. (ii)Oxygen gas exists as O2 molecules while sulfur exists as S8 rings. Since the electron clouds around sulphur extend out farther from the sulphur nucleus than the electron cloud around oxygen, they can have a greater effect through London Dispersion forces. The electron cloud of oxygen is less polarizable (squishy) than that of sulphur because the electrons are more tightly held by the oxygen nucleus so the forces between molecules is less for oxygen, O2, than those associated with the S8 molecule. (iii) Not all halogens are colored. Like dichloromethane, dichloroethane, chloroform, carbon tetra chloride. They are colorless liquids. In general, coloring is due to high electron density and number of free resonating electrons. Δ OR (i) 2NH4Cl + Ca(OH)2 → CaCl2 + 2H2O + 2NH3. (ii)C12H22O11(s) + H2SO4(aq) + 1/2 O2(g) → 11C(s) + CO2(g) + 12H2O(g) + SO2(g)

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(b)The Contact Process of sulphur trioxide production must be economically efficient for the manufacture of the important industrial chemical sulphuric acid. V2O5

2SO2(g) + O2(g) 2SO3(g) (ΔH = –196 kJ mol–1) The use of the V2O5 catalyst ensures a fast reaction without having to use too a higher temperature which would begin to favour the left hand side too much (energy change equilibrium rule), but remember a catalyst does not affect the % yield or equilibrium concentration of SO3, you just get there more economically faster.