Physical Chemistry Class-12 Chapter-3 Electrochemistry Most VVI Objective Questions

Q.1. Faraday’s 2ⁿd law of electrolysis and related to

(A) atomic number of the cation

(B) atomic number of the aniom

(C) equivalent weight of the electrolyte

(D) speed of cation

Ans :- (C)

Q.2. Which of the following is not a man – electrolyte ?


(B) glucose


(D) urea

Ans :- (A) 

Q.3. The unit of cell constant is of

(A) Ω⁻

(B) Ω⁻cm⁻¹

(C) Cm⁻¹

(D) Ω cm

Ans :- (C)

Q.4. The electrolytes that ionise completely in water are called

(A) strong electrolytes

(B) weak electrolytes

(C) strong and weak electrolytes

(D) metallic conductors

Ans :- (A)

Q.5. On the basis of electrochemical series which among the following metals do not give hydrogen by the reaction with dilute acids ?

(A) Ca, Sr, Ba

(B) Cu, Ag, Au

(C) Zn, Fe, Pb

(D) Na, Zn, Al, Cu

Ans :- (B)

Q.6. Which of the following is a secondary cell ?

(A) leclanche cell

(B) lead storage battery

(C) Concentration cell

(D) all of these

Ans :- (B)

Q.7. Among the following which metal can be recovered by the electrolysis of aqueous solution of metal salt ?

(A) Na

(B) Al

(C) Ca

(D) Ag

Ans :- (D)

Q.8. Which of the following is a ful cell ?

(A) Ni – Cd

(B) H₂ – O₂

(C) H₂ – Cl₂

(D) Zn – Cu

Ans :- (B)

Q.9. The in creasing order or reducing power of Mg, K, Fe and Zn metals .

(A) K < Mg < Fe <Zn

(B) K< Mg < Zn < Fe

(C) Fe < Zn < Mg < K

(D) Zn < Fe < Mg < K

Ans :- (C)

Q.10. Which among the following is the strongest oxidising agent

(A) F₂

(B) Cl₂

(C) Br₂

(D) I₂

Ans :- (A)

Q.11. With in crease in temperature, the conductivity of metal .

(A) increases

(B) decreases

(C) remains unchanged

(D) becomes doubled

Ans :- (B)

Q.12. The electrode potential of a standard hydrogen electrode is zero because

(A) it is very easy to oxidise hydrogen

(B) the electrode potential of hydrogen is considered as zero

(C) hydrogen atom has only one electron

(D) hydrogen is the lightest element

Ans:- (B)

Q.13. the standard electrode potentials for the half cell reactions are                                            Zn – Zn⁺⁺ + 2e⁻                      E⁰ = + 0.76 v                 Fe – Fe⁺⁺ + 2e⁻                      E⁰ = + 0.41 v the E.M.F. of the cell reaction Zn + Fe⁺⁺ – Zn⁺⁺ + Fe is

(A) – 0.35 v

(B) + 0.35 v

(C) – 1.17 v

(D) + 1.17 v

Ans :- (A)

Q.14. the highest conductivity is of

(A) silicon

(B) iron

(C) silver

(D) teflon

Ans :- (C)

Q.15. The value of specific conductance is the same as the conductance when

(A) the value of  cell constant is zero

(B) the value of cell constant is one

(C) the electr40de is made of copper

(D) the size of cell is very large

Ans :- (B)

Q.16. The conductivity of a solution is proportiond to

(A) dilution

(B) number of ions

(C) density of electric current

(D) volume of solution

Ans :- (B)

Q.17. Pure water does not conduct electricity because it is

(A) basic

(B) almost not ionised

(C) decomposed easily

(D) acidic

Ans :- (B)

Q.18. Which among the following substance is not present in a mercury cell

(A) HgO


(C) Zn

(D) HgCl₂

Ans :- (D)

Q.19. Which among the following halogen acids is the strongest reducing agent

(A) HCl

(B) HBr

(C) HI

(D) Hf

Ans :- (C)

Q.20. The unit of conductivity is

(A) ohm⁻¹

(B) ohm⁻¹ cm⁻¹

(C) ohm⁻¹ cm² equiv⁻¹

(D) ohm⁻¹ cm⁻²

Ans :- (B)

Q.21. Cell reaction is spontaneous (feasible) when

(A) E⁰ cell is negative

(B) ΔG is negative

(C) ΔG is positive

(D) none of these

Ans :- (B)

Q.22. As lead storage battery is charged

(A) lad dioxide dis solves

(B) sulphuric acid is regenerated

(C) lead metal gets coated with lead sulphate

(D) the concentration of sulphuric acid decreases

Ans :- (B)

Q.23. Fused NaCl on electrolysis gives ……….. on cathode

(A) chlorine

(B) sodium

(C) sodium amalgam

(D) hydrogen

Ans :- (B)

Q.24. During electrochemical process

(A) Gibbs free energy increases

(B) Gibbs free energy remains constant

(C) No predication can be made about Gibbs free energy

(D) Gibbs free energy decreases

Ans :- (D)

Q.25. When one faraday of electric current is passed the mass deposited is equal to

(A) One gram equivalent

(B) One gram male

(C) electrochemical equivalent

(D) half gram equivalent

Ans :- (A)

Q.26. Which among the following metal does not react with copper sulphate (CuSO₄)

(A) Fe

(B) Zn

(C) Mg

(D) Ag

Ans :- (D)

Q.27. If a salt bridge is suddenly removed from the cell then the voltage of the cell

(A) increases

(B) decreases

(C) becomes zero

(D) can be increases this depends on the cell reaction

Ans :- (C)

Q.28. Which of the following is an insulator

(A) Graphite

(B) Aluminium

(C) diamond

(D) silicon

Ans :- (C)

Q.29. When the cell reaction acquire the state of equilibrium then at that time E.M.F. of the cell is

(A) zero

(B) positive

(C) Nagative

(D) Indefinits

Ans :- (A)

Q.30. Which among the following is obtained at anode by the electrolysis of dilute solution of H₂SO₄ is

(A) H₂

(B) SO⁻²₄

(C) SO₂

(D) O₂

Ans :- (D)

Q.31. The most appropriate method used for plating of iron to protect from rusting is

(A) Nickel plating

(B) copper plating

(C) tin plating

(D) zinc plating

Ans :- (D)

Q.32. Which among the following substance is kept in a copper vessel safely

(A) ZnSO₄

(B) AgNO₃

(C) AuCl₃

(D) All of these

Ans :- (A)

Q.33. The electrode potential of a half cell depends on

(A) the nature of metal

(B) the inteation of metal ions in solution

(C) temperature

(D) all of these

Ans :- (D)

Q.34. Which among the following represents the relationship between conductivity and resistance of a conductor ?

(A) C α R

(B) C = R

(C) C = 1/R

(D) C = iR

Ans :- (C)

Q.35. The best conductor of electricity is 1 M solution of

(A) Glycerol

(B) HCl

(C) Acetic acid

(D) pure water

Ans :- (B)

Q.36. If 96500 coulomb of electricity is passed through CuSO₄ solution. it will liberate

(A) 63.5 g Cu

(B) 31.76 g Cu

(C) 96500 g Cu

(D) 100 g Cu

Ans :- (B)

Q.37. The conductivity of strong electrolyte

(A) increases slightly upon dilution

(B) decreases upon dilution

(C) does not change upon dilution

(D) depends upon density of solution

Ans :- (A)

Q.38. Which one is the Ionic compound ?

(A) Alchool

(B) Hydrogen chloride

(C) Sugar

(D) Sodium Nitrate

Ans :- (D)

Q.39. How many electrons are there in one coulomb of electricity ?

(A) 6.02 × 10²³

(B) 1.64 × 10⁻²⁴

(C) 6.24 × 10¹⁸

(D) 6.24 × 10⁻²⁴

Ans :- (C)

Q.40. The metal used to recover copper from solution of CuSO₄ is

(A) Fe

(B) He

(C) Na

(D) Ag

Ans :- (A)

Q.41. The standard electrode potential is measured by

(A) Electrometer

(B) Voltmeter

(C) Pyrometer

(D) Galvanometer

Ans :- (B)

Q.42. Which among the following statement is correct for Zn⁻ CuSo₄ cell ?

(A) the flow of electron is form copper to zinc

(B) E⁰red copper is less than E⁰red of zinc

(C) Zinc acts as anode and copper acts as cathode

(D) all the above statements are correct

Ans :- (C)

Q.43. The device in wich the combustion energy of fules like hydrogen and methane is directly converted in to electrical energy is called

(A) dynamo

(B) Ni – cd cell

(C) fuel cell

(D) electrolytic cell

Ans :- (C)

Q.44. Na is used in reduction of Zn salt because

(A) E⁰ zn(oxi) >E⁰ Na(oxi)

(B) E⁰zn(red) < E⁰Na(red)

(C) E⁰zn(oxi) < E⁰Na(oxi)

(D) Both ‘A’ and ‘B’

Ans :- (C)

Q.45. The amount of electricity which liberates 108 gm of Ag from AgNO₃ solution , is

(A) 1 Faraday

(B) 1 Ampere

(C) 1 Coloumb

(D) None of these

Ans :- (A)






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