chemistry multiple choice questions

CHEMISTRY MULTIPLE CHOICE QUESTIONS

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CLASS-12th

1. Which of the following aqueous solutions should have the highest boiling point?

(i) 1.0 M NaOH

(ii) 1.0 M Na2SO4

(iii) 1.0 M NH4NO3

(iv) 1.0 M KNO3

2.Which of the following binary mixtures will have same composition in liquid and

vapour phase?

(i) Benzene – Toluene

(ii) Water-Nitric acid

(iii) Water-Ethanol

(iv) n-Hexane – n-Heptane

3. The quantity of charge required to obtain one mole of aluminium from Al2O3 is

___________.

(i) 1F

(ii) 6F

(iii) 3F

(iv) 2F

4.While charging the lead storage battery ______________.

(i) PbSO4 anode is reduced to Pb.

(ii) PbSO4 cathode is reduced to Pb.

(iii) PbSO4 cathode is oxidised to Pb.

(iv) PbSO4 anode is oxidised to PbO2.


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5.Consider Fig. and mark the correct option.

(i) Activation energy of forward reaction is E1 + E2 and product is less stable than

reactant.

(ii) Activation energy of forward reaction is E1 + E2 and product is more stable than

reactant.

(iii) Activation energy of both forward and backward reaction is E1 + E2 and reactant is

more stable than product.

(iv) Activation energy of backward reaction is E1 and product is more stable than

reactant.

6.According to Maxwell Boltzmann distributon of energy, __________.

(i) the fraction of molecules with most probable kinetic energy decreases at higher

temperatures.

(ii) the fraction of molecules with most probable kinetic energy increases at higher

temperatures.

(iii) most probable kinetic energy increases at higher temperatures.

(iv) most probable kinetic energy decreases at higher temperatures.

7.A Lead storage battery is the most important type of secondary cell having a lead

anode and a grid of lead packed with PbO2 as cathode. A 38% solution of sulphuric

acid is used as electrolyte. (Density=1.294 g mL-1) The battery holds 3.5 L of the acid.

During the discharge of the battery, the density of H2SO4 falls to 1.139 g mL-1 . (20%

H2SO4 by mass)


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(1) Write the reaction taking place at the cathode when the battery is in use.

(2) How much electricity in terms of Faraday is required to carry out the reduction of

one mole of PbO2?

(3) What is the molarity of sulphuric acid before discharge?

(4) Lead storage battery is considered a secondary cell. Why?

(5) Write the products of electrolysis when dilute sulphuric acid is electrolysed using

Platinum electrodes.

8.Predict the number of ions produced per formula unit in an aqueous solution

of [Co(en)3]Cl3

(a) 4

(b) 3

(c) 6

(d) 2

9.When one mole of CoCl3.5NH3 was treated with excess of silver nitrate

solution, 2 mol of AgCl was precipitated. The formula of the compound is:

(a) [Co(NH3)5Cl2]Cl

(b) [Co(NH3)5Cl]Cl2

(c) [Co(NH3)4Cl2] (NH3)Cl

(d) [Co(NH3)3Cl3] (NH3)2

10.The incorrect statement about LDP is:

(a) It is obtained through the free radical addition of ethene.

(b) It consists of linear molecules.


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(c) It is obtained by the H-atom abstraction.

(d) Peroxide is used as an initiator.

11.The absorption maxima of several octahedral complex ions are as follows:

S.No Compound max nm

1 [Co(NH3)6]3+ 475

2 [Co(CN)6]3-

310

3 [Co(H2O)6]3+ 490

The crystal field splitting is maximum for :

(a) [Co(H2O)6]3+

(b) [Co(CN)6]3-

(c) [Co(NH3)6]3+

(d) All the complex ions have the same splitting,Do

12.Which of the following electrolytes will have maximum coagulating value for

AgI/Ag+ sol?

(i) Na2S

(ii) Na3PO4

(iii) Na2SO4

(iv) NaCl

13.Which of the following curves is in accordance with Freundlich adsorption

isotherm?


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14.Which of the following process is not responsible for the presence of electric charge

on the sol particles?

(i) Electron capture by sol particles.

(ii) Adsorption of ionic species from solution.

(iii) Formation of Helmholtz electrical double layer.

(iv) Absorption of ionic species from solution.

15.When copper ore is mixed with silica, in a reverberatory furnace copper matte is

produced. The copper matte contains ____________.

(i) sulphides of copper (II) and iron (II)

(ii) sulphides of copper (II) and iron (III)

(iii) sulphides of copper (I) and iron (II)

(iv) sulphides of copper (I) and iron (III)

NOTE: Answer the question 16-18 on the basis of Fig.6.1


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16.Choose the correct option of temperature at which carbon reduces FeO to iron and

produces CO.

(i) Below temperature at point A.

(ii) Approximately at the temperature corresponding to point A.

(iii) Above temperature at point A but below temperature at point D.

(iv) Above temperature at point A.

17.Below point ‘A’ FeO can ______________.

(i) be reduced by carbon monoxide only.

(ii) be reduced by both carbon monoxide and carbon.

(iii) be reduced by carbon only.


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(iv) not be reduced by both carbon and carbon monoxide.

18.For the reduction of FeO at the temperature corresponding to point D, which of the

following statements is correct?

(i) ΔG value for the overall reduction reaction with carbon monoxide is zero.

(ii) ΔG value for the overall reduction reaction with a mixture of 1 mol carbon and 1

mol oxygen is positive.

(iii) ΔG value for the overall reduction reaction with a mixture of 2 mol carbon and 1

mol oxygen will be positive.

(iv) ΔG value for the overall reduction reaction with carbon monoxide is negative.

19.In which of the following polymers ethylene glycol is one of the monomer units?

20.


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21.The reaction of aniline with chloroform under alkaline conditions leads to the

formation of..

A) Phenyl cyanide

(B) Phenyl isonitrile

(C) Phenyl cyanate

(D) Phenyl isocyanate

22.Which of the following statements about primary amines is ‘False‘?

(A) Alkyl amines are stronger bases than aryl amines

(B) Alkyl amines react with nitrous acid to produce alcohols

(C) Aryl amines react with nitrous acid to produce phenols

(D) Alkyl amines are stronger bases than ammonia

23.Which of the following compounds is aromatic alcohol?

i) A, B, C, D

(ii) A, D

(iii) B, C

(iv) A


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24.Mark the correct order of decreasing acid strength of the following compounds..

A)e > d > b > a > c

B)b > d > a > c > e

C)d > e > c > b > a

D)e > d > c > b > a

25.CH3CHO and C6H5CH2CHO can be distinguished chemically by:

A)Tollen's reagent test

B)Fehling solution test

C)Benedict test

D)Iodoform test

26.The correct order of decreasing acid strength of trichloroacetic acid (A),

trifluoroacetic acid (B), acetic acid (C) and formic acid (D) is

A)A > B > C > D

B)A > C > B > D

C)B > A > D > C

D)B > D > C > A

27.Identify the compound Y in the following reaction.


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28.Which of the following is halogen exchange reaction?

29.What is ‘A’ in the following reaction?


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30.Which is the correct increasing order of boiling points of the following compounds?

1-Iodobutane, 1-Bromobutane, 1-Chlorobutane, Butane

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

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

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

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

chemistry multiple choice questions

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