2552chem guess paper

8/13/2019 2552Chem Guess Paper

1/7

SCIENCE Guess Paper

Paper 2 ( Chemistry )

( One hour and a half )Answers to this paper must be written on paper provided separately

You will not be allowed to write during the first 15 minutes.

This time is to be spent in reading the Question Paper.

The time given at the head of this Paper is the time allowed for writing the answers.

Attempt all questions fromSection - Iand any FOUR questions fromSection - II.

The intended marks for questions or parts of questions, are given in brackets [ ].

SECTION - I( 40 Marks )

Attempt all questions from this section

Question : 1

(a)

(b)

From the following list of acids, choose the one acid in each case, which matches the description

[ 1 ] to [ 6 ] given below : -

11.. The acid present in three parts by volume in aqua regia.

22.. The acid which reacts with zinc and liberate sulphur dioxide gas.

33.. The acid which reacts with barium chloride to give a white precipitate.

44.. The acid which react with FeSO4and Conc. Sulphuric acid and liberate nitric oxide.

55.. The acid which reacts with Pb (NO3)2and give a white ppt. which is soluble in hot water.

66.. The acid which reacts with copper turnings and liberate nitrogen dioxide gas.

The following questions pertain to chemical bonding : -

1. Differentiate between the terms :Polar covalent compounds & Non - polar covalent compounds.

2. Draw the Lewis electron dot structure for the following compounds : i. Calcium oxide ii. Magnesium chloride molecule

[ 6 ]

[ 4 ]

[email protected]

FPT A -12 turn over

Conc. Sulphuric acid, Conc. Hydrochloric acid, Conc. Nitric acid,

Dilute Sulphuric acid, Dilute Hydrochloric acid, Dilute Nitric acid


2/7

Pg - 2

(c)

(d)

Choose the correct word or phrase from the brackets to complete the following sentences : -

1. A metallic sulphide ore containing lead is _____________________ [ cinnabar, barite, galena ].2. The reduced product obtained when sulphur dioxide is bubbled into chlorine water is

______________________________ [ sulphuric acid, hydrochloric acid, sulphur ].

3. Dry chlorine reacts with dry sulphur dioxide in presence of sunlight to give_______________________ [ sulphur monochloride, sulphuryl chloride, sulphurous chloride ].

4. Concentrated sulphuric acid reacts with ethyl alcohol at 170 C to give the dehydrated product_____________________________________________ [ ethane, ethene, ethyne ].

5. When hydrogen sulphide gas is bubbled through zinc nitrate solution a___________________________ [ black, white, yellow] precipitate of zinc sulphide is obtained.

Study the diagram given below and answer the following the questions : -

[ 5 ]

1. Give name of electrodes A and B.2. Which electrode is oxidizing electrode, A or B ?3. Write chemical equation which takes place at the cathode and at the anode when very dilute

sulphuric acid is electrolysed.

4.

If the electrolytic cell is used for electroplating of an article with silver metal ;

Name the electrolyte used and the electrode where article to be plated is placed.

[ 1 ]

[ 1 ]

[ 2 ]

[ 2 ][email protected]

FPT A -12 Contd .. Pg3

+

A B


3/7

Pg 3

(e)

(f)

(g)

What do you observe in each of the following reactions :

11.. Copper [ II ] sulphate is electrolysed using platinum electrodes.

22.. Conc. sulphuric acid is added to ethyl alcohol at elevated temperatures and the gas liberated is

bubbled through a solution of alkaline potassium permanganate solution.

33.. Crystals of lead nitrate are heated strongly in a test tube.

44.. Few drops of silver nitrate solution is added to dil. hydrochloric acid solution in a test tube.

55.. Sulphur dioxide gas passed through chlorine water containing barium chloride in it.

66.. Ethyne gas passed through alkaline potassium permanganate solution.

Write balanced equations for each of the following reactions : -

1. Manganese dioxide and concentrated Hydrochloric acid.2. Warm water added to magnesium nitride.3. Warm water added to calcium carbide.4. Sulphur dioxide passed through aqueous solution of ferric chloride.5. Concentrated sulphuric acid added to sulphur.Solve the following : -

1. When a mixture of ethyne and oxygen are ignited, carbon dioxide and water vapour areformed as the products of combustion. If the volume of the product carbon dioxide at s.t.p. is

found to be 200 cc., calculate the volume of ethyne in the original mixture

2. A hydrocarbon contains 17.25% of hydrogen. lf its molecular weight is 58, determine itsmolecular formula and give its IUPAC name. [ C = 12., H = 1 ]

3. Taking Avogadros number as 6 x 1023. Calculate the number of molecules in 3.65 g. ofhydrogen chloride gas. [ H = 1, Cl = 35.5 ]

[ 6 ]

[ 5 ]

[ 2 ]

[ 4 ]

[2 ]

[email protected]

FPT A -12 turn over


4/7

Pg - 4

(a)

(b)

(a)

SECTION - II( 40 Marks )

Attempt any four questions from this section

Question : 2

Salts are prepared in the laboratory using different reactants such as : -

A : Insoluble hydroxide + dilute acid

B : Soluble hydroxide + dilute acid

C : Metal + dilute acid

D : Metal + non-metal

E : Salt solution [ 1 ] + salt solution [ 2 ]

State the method A, B, C, D or E used for the following salt preparations.

(i) Calcium carbonate (ii) Sodium sulphate (iii) Zinc sulphate

(iv) Lead nitrate (v) Ferric chloride

Give a chemical test to distinguish between the following :-

1. Sodium chloride and sodium nitrate using concentrated acid and liquor ammonia.2. Sodium sulphite and sodium sulphate using barium chloride and dil. hydrochloric acid.3. Zinc nitrate and lead nitrate using liquor ammonia.4. Ethane and ethyne using solution of bromine in CCl4.5. Ethanol and Ethanoic acid using neutral ferric chloride solution.Question : 3

State which chemical property of ( H2SO4 / SO2 / HCl ) is involved in the followingconversions : -

1. C12H22O11 + H2SO4 12 C + H2SO4 . 22 H2O2. Br2 + 2 H2O + SO2 2 HBr + H2SO43. 2 Mg + SO2 2 MgO + S4. Na2CO3 + 2 HCl 2 NaCl + H2O + CO25. CaOCl2 + HCl CaCl2 + H2O + Cl2

[ 5 ]

[ 5 ]

[ 5 ]

[email protected]

FPT A -12 Contd .. Pg5


5/7

Pg - 5(b)

(a)

(b)

(c)

(d)

(a)

Compare the elements of group - 1 ( I A ) with elements of group - 17 ( VII A ) with respect to the

following properties : -

1. Number of valence electrons.2.

Nature of oxide formed when the elements react with oxygen.

3. Conduction of electricity.4. Oxidizing / reducing nature of the elements.5. Metallic / non-metallic character.

Question : 4

1. State Gay Lussacs Law.2. If 200 cm3 of ethane was exploded with 1200 cm3of oxygen, calculate the volume of unused

oxygen.

1. State Avogadro's Law.2. Calculate the relative molecular mass of a gas X, 112 ml. of which has a mass of 0.22 g. at s.t.p.

Ammonia is prepared in the laboratory by action of heat on calcium hydroxide and ammonium

sulphate.

1. Write the balanced equation for the reaction.2. Calculate the volume and number of moles of ammonia gas liberated when 7.92 g. of the

ammonium salt is heated with the excess alkali. [ Ca = 40, N = 14, H = 1, S = 32, O = 16 ]

3. Give a reason why the above alkali is preferred to other caustic alkalis.Give the chemical name of the following ores : -

1. Calamine. 2. Cryolite.Question : 5

Answer the following : -

1. Name the common metal present in the alloys bell metal ' & type metal'.2. State the property of the alloy German silver' which makes it useful in the manufacture of

decorative articles.

[ 5 ]

[ 1 ]

[ 1 ]

[ 1 ]

[ 1 ]

[ 1 ]

[ 2 ]

[ 1 ]

[ 2 ]

[ 2 ]

[email protected]

FPT A -12 turn over


6/7

Pg - 6(b)

(c)

(a)

(b)

Name the following hydrocarbons : -

1. A saturated hydrocarbon which is oxidized by oxidizing agents such as potassium dichromate[ K2Cr2O7] to ethyl alcohol.

2. An unsaturated hydrocarbon which when bubbled through bromine solution in carbontetrachloride yields 1,1,2,2 - tetrabromo ethane.

3. An unsaturated hydrocarbon which undergoes polymerization to yield an important polymer orplastic.

4. A saturated hydrocarbon which is used in the preparation of chloroform an anesthetic agent.5. An unsaturated hydrocarbon which when bubbled through chlorine water yields 1, 2 - dichloro

ethane

Give the IUPAC name of the following hydrocarbons : -

1. 2.

3.

Question : 6

The following questions are related with the metallurgy of Aluminium.

1. Name the most common ore of Aluminium and give its formula.2. Name the process used for the purification of the above mentioned ore.3. Give equations for all three reactions taking place during concentration of ore.

Write balanced chemical equation for the following :

1. Catalytic oxidation of Ammonia.2. Catalytic oxidation of Sulphur dioxide.3. Oxidation of Ethane when passed through copper tube at 200 o C.

[ 5 ]

[ 3 ]

[ 5 ]

[ 3 ]

[email protected]

FPTA -12 Contd .. Pg7

CH3l

H3C C CH2 C = Ol l

CH3 OH

CH3l

H3C CH CH2C = CH CH3l

C2H5

CH3l

H3C CH C CH


7/7

Pg 7

(c)

(a)

(b)

(c)

Give reasons why :

1. Before the preparation of anhydrous ferric chloride, chlorine gas is passed through

concentrated sulphuric acid.

2. During the laboratory preparation of nitric acid, all apparatus are made of glass.

Question : 7

Copy and complete the following table for Haber's process : -

Ratio of

Raw materialsCatalyst Promoter Temperature Pressure Product

Elements A, B and C have electronic configuration 2, 8, 8, 1; 2, 6 and 2, 8, 3 respectively.

Answer the following questions in terms of A, B, C : -

1. Mention to which Period and Group does element C belongs.2. Which of the two metals mentioned above is least reactive.3. Mention the type of bond formed between the elements A and B4. Give molecular formula for the compound formed between elements A and C.1. Explain the term periodic properties'.2. State one periodic property of an element which : -

i. Decreases on moving from left to right in a period from group 1 A to group VII A.ii. Increases on moving from left to right in a period from group 1 A to group VII A.

[ 2 ]

[ 3 ]

[ 4 ]

[ 1 ]

[ 2 ]

[email protected] Mr. Rajendra Burriwar, M.Sc., B.Ed.

FPTA -12

2552chem guess paper

Documents