thesportszones.com – MCQs, Mock Tests | IIT JEE IIT JEE Redox Reactions And Electrochemistry

1 It is impossible to measure the actual voltage of any half cell by itself because

A of resistance of wire B electrical neutrality is maintained C a reaction does not take place of its own D both half cell reactions occur simultaneously

✅ Correct Answer: 4

2 An electrochemical cell can be changed into an electrolytic cell by

A changing the electrolytes in two half cells B changing the conc. of the electrolytes C providing higher potential from outside D reversing the electrodes

✅ Correct Answer: 3

3 .In electrolysis, one mole of aluminium atoms is deposited by

A five moles of electrons B three moles of electrons C two moles of electrons D one mole of electrons

✅ Correct Answer: 2

4 .During discharge in the case of lead storage batteries density of sulphuric acid increases remains constant

A increases B decreases C may decrease or increase D remains constant

✅ Correct Answer: 2

5 .For reducing 1 mole of ferrous ions to iron the number of faradays of electricity required will be

A 4 B 1.5 C 0.5 D 1

✅ Correct Answer: 1

6 One mole of electrons is same as faraday

A faraday B coulomb C ampere D none of these

✅ Correct Answer: 2

7 The decomposition of an electrolyte by passing electric current depends upon

A energy of electrolysis B quantity of current which is passed C shape of the electrode D size of the container

✅ Correct Answer: 2

8 .Which of the following is the best reducing agent in aqueous solution?

A Li B Cs C Rb D K

✅ Correct Answer: 1

9 If mercury is used at cathode during the electrolysis of aqueous NaCl the ions discharged at the cathode are

A hydroxide B chloride C sodium D none of these

✅ Correct Answer: 3

10 Salt Bridge is used because it

A forms insoluble precipitates with the electrolytes in the two half cells B enhances the flow of electrons by overcoming liquid junction potential C maintains the electrical neutrality of the two half cells D provides the extra ions

✅ Correct Answer: 3

11 .On passing one faraday of electricity through molten lead (II) bromide, amount of bromine obtained is 1 gm equivalent

A 5 gm mole B 5 gm mole C 3 mole D 1 mole gm atom

✅ Correct Answer: 4

12 .During the electrolysis of fused sodium chloride, the anodic reaction is

A reduction of chloride ions B oxidation of sodium ions C oxidation of chloride ions D None of the above

✅ Correct Answer: 3

13 More electropositive elements have more

A negative reduction potential B positive oxidation potential C tendency to loose electrons D positive reduction potential

✅ Correct Answer: 1

14 In the concentration cells the electrical energy is due to

A transfer of a substance from one solution to another solution B temperature C reduction of fuel D chemical action

✅ Correct Answer: 1

15 The most important condition for a galvanic cell is

A the two half cells should be connected internally by some device B the electrolytes should taken in a separate container C the electrolytes should not have physical contact D the electrodes should be inert

✅ Correct Answer: 1

16 .Passing 96.5 coulombs of charge through molten NaOH will deposit

A 0.046 g B 0.023 g C 230 g D 46 g

✅ Correct Answer: 2

17 Which of the following metals when coupled will give maximum e.m.f. for a voltaic cell.

A Pb and Sn B Cu and Ag C Ca and Cu D Fe and Cu

✅ Correct Answer: 3

18 Art of electroplating was enunciated by Brugantally

A Einstein B Brugantally C Ampere D Kohlorausch

✅ Correct Answer: 2

19 Electrochemical equivalent is the mass of the element liberated during electrolysis when

A 2 faraday electricity is passed B 1 amp. current for 1 hrs is passed C 1 coulomb electricity is passed D 3 amp current is passed

✅ Correct Answer: 3

20 .Hydroxide ions are discharged in reference to chloride ions when?.is electrolysed.

A NaCl B solid NaCl C dil. NaCl D conc. NaCl

✅ Correct Answer: 3

21 .Which of the following is not a good conductor?

A Silver B Solid NaCl C Fused NaCl D Aqueous solution of NaCl

✅ Correct Answer: 2

22 .Aqueous solution of HCl conducts electricity because it

A dissociates B dimerises C ionises D forms hydrogen bond

✅ Correct Answer: 3

23 .At infinite dilution of an electrolyte, the equivalent conductance of cations and anions are

A dependent on the nature of solvent B independent of nature of ions C independent of each other D dependent on each other

✅ Correct Answer: 2

24 .The quantity of an ion discharged during electrolysis is directly proportional to

A chemical equivalent of the ion B time of flow of current C current strength D All the above

✅ Correct Answer: 4

25 Substances that dissociate and conduct electricity in aqueous solutions are conductors

A emulsios B colloidal solution C electrolytes D conductors

✅ Correct Answer: 4

26 .The electrode by which electrons enter the electrolyte may be

A cathode B conductor C anode D anode or cathode

✅ Correct Answer: 1

27 Voltaic cell stops functioning after sometimes because there is increase in oxidation potential and decrease in reduction potential

A the decrease in oxidation potential outweigh the increase in reduction potential B the decrease in oxidation potential value equalises the increase in reduction potential value C decrease in oxidation potential value D increase in oxidation potential and decrease in reduction potential

✅ Correct Answer: 2

28 .On passing electricity through dil sulphuric acid the amounts of substance liberated at the cathode and anode are in the ratio

A 2:03 B 3:02 C 8:01 D 1:08

✅ Correct Answer: 4

29 .The conduction of electricity through the electrolyte solution is due to

A movement of molecules of electrolyte B movement of ions of electrolyte C movement of separate atoms D movement of particles of the solvent.

✅ Correct Answer: 2

30 .The chemical reaction taking place at anode is

A halogenation B oxidation C ionisation D reduction

✅ Correct Answer: 2

31 Certain quantity of current librated 0.504 g of hydrogen in 2 hr. The number of grams of copper that can be librated by same current under similar conditions will be approximately

A 12.7 g B 16.0 g C 31.8 g D 63.5 g.

✅ Correct Answer: 2

32 A certain quantity of current i amp was passed through three electrolytic cells P, Q, R connected in series and containing aqueous solutions of silver nitrate, mercuric nitrate and mer-curous nitrate respectively. It resulted in the deposition of0.216 g of Ag. The masses of Hg deposited in cell Q andR respectively (At. = 108; Hg = 200.6)

A 0.4012 g, 0.9042 g B 0.4012 g, 0.2006 g C 0.2006 g, 0.4012 g D 0.1003 g, 0.2006 g.

✅ Correct Answer: 3

33 During the electrolysis of water 4 mol of electrons were transferred from anode to cathode. The total volume of the gases produced at STP will be approximately

A 67.2 L B 22.4 L C 44.8 L D 89.4 L.

✅ Correct Answer: 1

34 A bulb draws a current of 4.0 ampere, the charge in coulombs used by the bulb in 30 seconds is

A 60 C B 120 C C 15 C D 7.5 C.

✅ Correct Answer: 2

35 The conductivity of strong electrolyte increase on dilution slightly

A increase on dilution slightly B does not change on dilution C decreases on dilution D depends on density of electrolyte itself.

✅ Correct Answer: 1

36 .Amount of chlorine liberated while passing 0.5 faraday of electricity through NaCl solution is

A 63 g B 17.75 g C 35.5 g D 8.25 g

✅ Correct Answer: 2

37 .In an electrochemical cell, electrical energy

A may be absorbed or released B neither supplied nor released C has to be supplied D is released

✅ Correct Answer: 4

38 When electricity is passed to aqueous solution of aluminium chloride, 13.5 g of Al are deposited. The number of Faradys of electricity passed must be

A 2 B 1.5 C 1 D 0.5

✅ Correct Answer: 2

39 .Two electrolytic cell contain 0.1 M ferrous sulphate and 0.2 M ferric chloride respectively are subjected to electrolysis, the ratio of iron deposited in the two cells is

A 1:01 B 2:01 C 3:01 D 3:02

✅ Correct Answer: 4

40 The equivalent conductivity of a weak electrolyte

A increases rapidly with dilution but does not reach a B constant value even at infinite dilution C reaches a maximum constant value at infinite dilution D is a constant and does not change with dilution

✅ Correct Answer: 1

41 Point out the correct statement in a cell of zinc and copper:

A Zinc acts as anode and copper as cathode B The E of zinc is more than that of copper C The flow of electrons is from copper to zinc D Zinc acts as cathode and copper as anode

✅ Correct Answer: 1

42 .The amount of electricity that can deposit 108 g of silver

A 1 amp. B 1 coulomb C 1 Faraday D 2 amp.

✅ Correct Answer: 3

43 An ampere is the rate of flow of electric current of:

A one coulomb per second B one faraday per minute C one coulomb per minute D one faraday per second

✅ Correct Answer: 1

44 .The most reactive metals among the following is Mg

A Mg B Rb C Al D Na

✅ Correct Answer: 1

45 If the specific conductance and conductance of a solution are the same, then the cell constant is 8

A 25 B 10 C 8 D 9

✅ Correct Answer: 2

46 In a galvanic cell, which one of the following statements is incorrect?

A Reduction takes place at the anode B Reduction takes place at the cathode C Cathode is positively charged D Anode is negatively charged

✅ Correct Answer: 1

47 .The units of electrochemical equivalent is

A gram/second B gram/coulomb C gram/cm D gram/volt

✅ Correct Answer: 2

48 .A certain current liberated 0.504 g of hydrogen in 2 hours. How many grams of copper can be liberated by the same current flowing for the same time in a copper sulphate solution? 22.9 g

A 63.5 g B 31.8 g C 22.9 g D 55.8 g

✅ Correct Answer: 2

49 .Electrolytes when dissolved in water dissociate into their constituent ions. The degree of dissociation of an electrolyte increase with the

A decreasing concentration of the electrolyte B increasing concentration of the electrolyte C presence of a common constituent D decreasing temperature

✅ Correct Answer: 1

50 .Which of the following does not give conducting solution is water?

A Potash alum B Ethyl alcohol C Vitriol D Methyl Alcohal

✅ Correct Answer: 2

IIT JEE — Learn

IIT JEE Redox Reactions And Electrochemistry