chemistryChemistry class 12th English Medium

3. ELECTROCHEMISTRY Objective

3. ELECTROCHEMISTRY


1. If 96500 coulomb electricity is passed through CusO4 solution, it will liberate

(A) 63.5 gm of Cu
(B) 31.76 gm of Cu
(C) 96500 gm of Cu
(D) 100 gm of Cu

Show Answer
Answer ⇒ (B)

2. Fused NaCl on electrolysis gives …………… on cathode.

(A) Chlroine
(B) Sodium
(C) Sodium amalgam
(D) Hydrogen

Show Answer
Answer ⇒ (B)

3. The standard electrode potentials for the half cell reactions are :

Zn → Zn2+ + 2e- E° = + 0.76 V
Fe → Fe2+ + 2e- E° = + 0.41 V
The emf of the cell reaction Fe2+ + Zn → Zn2+ + Fe is

(A) – 0.35 V
(B) + 0.35 V
(C) – 1.17 V
(D) + 1.17 V

Show Answer
Answer ⇒ (B)

4. For a certain redox reaction, Eo is positive. This means that

(A) ΔG° is positive, K is greater than 1
(B) ΔG° is positive, K is less than 1
(C) ΔG° is negative, K is greater than 1
(D) ΔG° is negative, K is less than 1

Show Answer
Answer ⇒ (C)

5.Cell reaction is spontaneous, when

(A) E0red is negative
(B) ΔG° is negative
(C) E0oxid is positive
(D) ΔG° is positive

Show Answer
Answer ⇒ (B)

6. Equilibrium constant K is related to E0cell and not Ecell because

(A) E0cell is easier to measure than Ecell
(B) Ecell becomes zero at equilibrium point but E0cell remains constant under all conditions
(C) at a given temperature, Ecell changes hence value of K can’t be measured
(D) any of the terms Ecell or E0cell can be used

Show Answer
Answer ⇒ (B)

7. Molar conductivity of 0.15 M solution of  KC1 at 298 K, if its conductivity of 0.0152 S cm-1 will be

(A) 124 Ω-1 cm2 mol-1
(B) 204 Ω-1 cm2 mol-1
(C) 101 Ω-1 cm2 mol-1
(D) 300 Ω-1 cm2 mol-1

Show Answer
Answer ⇒ (C)

8. The specific conductivity of N/10 KCl solution at 20°C is 0.0212 ohm-1 cm-1 and the resistance of the cell containing this solution at 20°C is 55 ohm. The cell constant is

(A) 3.324 cm-1
(B) 1.166 cm-1
(c) 2.372 cm-1
(D) 3.682 cm-1

Show Answer
Answer ⇒ (B)

9. Faraday’s law of electrolysis is related to

(A) Atomic number of cation
(B) Speed of cation
(C) Speed of anion
(D) Equivalent weight of electrolyte

Show Answer
Answer ⇒ (D)

10. The molar conductivity is maximum for the solution of concentration

(A) 0.004 M
(B) 0.002 M
(C) 0.005 M
(D) 0.001 M

Show Answer
Answer ⇒ (D)

11. Units of the properties measured are given below. Which of the properties has been not matched correctly ?

(A) Molar conductance = Sm2 mol-1
(B) Cell constant = m-1
(C) Specific conductance of = S m2
(D) Equivalence conductance = S m2 (g eq)-1

Show Answer
Answer ⇒ (C)

12. How long would it take to deposit 50 g of Al from an electrolytic cell containing Al2O3 using a current of 105 ampere ?

(A) 1.54 h
(B) 1.42 h
(C) 1.32 h
(D) 2.15 h

Show Answer
Answer ⇒ (B)

13. The charge required for reducing 1 mole of MnO The charge required for reducing to Mn2+ is

(A) 1.93 x 105 C
(B) 2.895 x 105 C
(C) 4.28 x 105 C
(D) 4.825 x 105 C

Show Answer
Answer ⇒ (D)

14. If a current of 1.5 ampere flows through a metallic wire for 3 hours, then how many electrons would flow through the wire ?

(A) 2.25 x 1022 electrons
(B) 1.13 x 1023 electrons
(C) 1.01 X 1023 electrons
(D) 4.5 x 1023 electrons

Show Answer
Answer ⇒ (C)

15. How many coulombs of electricity is required to reduce 1 mole of Cr2O How many coulombs of electricity is required in acidic medium ?

(A) 4 96500 C
(B) 6 x 96500 C
(C) 2 x 96500 C
(D) 1 x 96500 C

Show Answer
Answer ⇒ (B)

16. How much time is required to deposit 1 X 10-3 cm thick layer of silver (density of 1.05 g cm-3) on a surface of area 100 cm2 by passing a current of 5 A through AgNO3 solution ?

(A) 125 s
(B) 115 s
(C) 18.7 s
(D) 27.25 s

Show Answer
Answer ⇒ (C)

17. How much metal will be deposited when a current on 12 ampere with 75% efficiency is passed through the cell for 3 h ? (Given : Z = 4 x 10-4)

(A) 32.4 g
(B) 38.8 g
(C) 36.0 g
(D) 22.4 g

Show Answer
Answer ⇒ (B)

18. An electrochemical cell can behave like an electrolytic cell when

(A) Ecell = 0
(B) Ecell > Eext
(C) Eext > Ecell
(D) Ecell = Eext

Show Answer
Answer ⇒ (C)

19. Use the data given below find out the strongest reducing agent.

Use the data given below find out the strongest

(A) Cl
(B) Mn2+
(C) MnO The charge required for reducing
(D) Cr3+

Show Answer
Answer ⇒ (D)

20. The quantity of charge required to obtain one mole of aluminium from A12O3 is

(A) 1 F
(B) 6 F
(C) 3 F
(D) 2 F

Show Answer
Answer ⇒ (C)

21. The cell constant of a conductivity cell

(A) changes with change of electrolyte
(B) changes with change of concentration of electrolyte
(C) changes with temperature of electrolyte
(D) remains constant for a cell

Show Answer
Answer ⇒ (D)

22. While charging the lead storage battery

(A) PbSO4 anode is reduced to Pb
(B) PbSO4 cathode is reduced to Pb
(C) PbSO4 cathode is oxidised to Pb
(D) PbSO4 anode is oxidised to Pbo2

Show Answer
Answer ⇒ (A)

23. In the electrolysis of aqueous sodium chloride solution which of the half cell reaction will occur at anode ?

(A) Na+(aq) +e → Na(s); E0cell = -2.71V
(B) 2H2IO(l) → O2 (g) + 4H+(aq) + 4e;E0cell = 1.23V
(C) H+(aq) + e → 1/2 H2 (g); E0cell = 0.00V
(D) Cl(aq) → 1/2 Cl2 (g)+e-;E0cell = 1.36V

Show Answer
Answer ⇒ (D)

 


24. When one faraday of electric current is passed, the mass deposited, is equal to

(A) One gram equivalent
(B) One gram mole
(C) electrochemical equivalent
(D) Half gram equivalent

Show Answer
Answer ⇒ (C)

25. The electrode through which electrons enter into electrolytic solution is

(A) Cathode
(B) Anode
(C) May be anode cathode
(D) None

Show Answer
Answer ⇒ (A)

Class 12th Chemistry Objective Question English

S.NCHEMISTRY OBJECTIVE English Medium
1SOLID STATE 
2SOLUTION
3ELECTROCHEMISTRY
4CHEMICAL KINETICS
5SURFACE CHEMISTRY
6GENERAL PRINCIPLES & PROCESSES OF ISOLATION OF ELEMENTS
7 THE P-BLOCK ELEMENTS
8 THE D- AND f-BLOCK ELEMENTS
9 CO-ORDINATION COMPOUNDS
10HALOALKANES AND HALOARENES
11ALCOHOLS, PHENOLS AND ETHERS
12ALDEHYDES, KETONES AND CARBOXYLIC ACIDS
13AMINES
14BIOMOLECULES
15 POLYMERS
16CHEMISTRY IN EVERYDAY LIFE

Back to top button