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
Answer тЗТ (B)
2. Fused NaCl on electrolysis gives …………… on cathode.
(A) Chlroine
(B) Sodium
(C) Sodium amalgam
(D) Hydrogen
Answer тЗТ (B)
3. The standard electrode potentials for the half cell reactions are :
Zn тЖТ Zn2+ + 2e- E┬░ = + 0.76 V
Fe тЖТ Fe2+ + 2e- E┬░ = + 0.41 V
The emf of the cell reaction Fe2+ + Zn тЖТ Zn2+ + Fe is
(A) – 0.35 V
(B) + 0.35 V
(C) тАУ 1.17 V
(D) + 1.17 V
Answer тЗТ (B)
4. For a certain redox reaction, Eo is positive. This means that
(A) ╬ФG┬░ is positive, K is greater than 1
(B) ╬ФG┬░ is positive, K is less than 1
(C) ╬ФG┬░ is negative, K is greater than 1
(D) ╬ФG┬░ is negative, K is less than 1
Answer тЗТ (C)
5.Cell reaction is spontaneous, when
(A) E0red is negative
(B) ╬ФG┬░ is negative
(C) E0oxid is positive
(D) ╬ФG┬░ is positive
Answer тЗТ (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
Answer тЗТ (B)
7. Molar conductivity of 0.15 M solution of┬а KC1 at 298 K, if its conductivity of 0.0152 S cm-1 will be
(A) 124 ╬й-1 cm2 mol-1
(B) 204 ╬й-1 cm2 mol-1
(C) 101 ╬й-1 cm2 mol-1
(D) 300 ╬й-1 cm2 mol-1
Answer тЗТ (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
Answer тЗТ (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
Answer тЗТ (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
Answer тЗТ (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
Answer тЗТ (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
Answer тЗТ (B)
13. The charge required for reducing 1 mole of MnO ┬аto 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
Answer тЗТ (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
Answer тЗТ (C)
15. How many coulombs of electricity is required to reduce 1 mole of Cr2O in acidic medium ?
(A) 4 96500 C
(B) 6 x 96500 C
(C) 2 x 96500 C
(D) 1 x 96500 C
Answer тЗТ (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
Answer тЗТ (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
Answer тЗТ (B)
18. An electrochemical cell can behave like an electrolytic cell when
(A) Ecell = 0
(B) Ecell > Eext
(C) Eext > Ecell
(D) Ecell = Eext
Answer тЗТ (C)
19. Use the data given below find out the strongest reducing agent.
(A) Cl–
(B) Mn2+
(C) MnO
(D) Cr3+
Answer тЗТ (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
Answer тЗТ (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
Answer тЗТ (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
Answer тЗТ (A)
23. In the electrolysis of aqueous sodium chloride solution which of the half cell reaction will occur at anode ?
(A) Na+(aq) +e– тЖТ Na(s); E0cell = -2.71V
(B) 2H2IO(l) тЖТ O2 (g) + 4H+(aq) + 4e–;E0cell = 1.23V
(C) H+(aq) + e– тЖТ 1/2 H2 (g); E0cell = 0.00V
(D) Cl–(aq) тЖТ 1/2 Cl2 (g)+e-;E0cell = 1.36V
Answer тЗТ (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
Answer тЗТ (C)
25. The electrode through which electrons enter into electrolytic solution is
(A) Cathode
(B) Anode
(C) May be anode cathode
(D) None
Answer тЗТ (A)
Class 12th Chemistry Objective Question English
S.N | CHEMISTRY OBJECTIVE English Medium |
1 | SOLID STATE┬а |
2 | SOLUTION |
3 | ELECTROCHEMISTRY |
4 | CHEMICAL KINETICS |
5 | SURFACE CHEMISTRY |
6 | GENERAL PRINCIPLES & PROCESSES OF ISOLATION OF ELEMENTS |
7 | THE P-BLOCK ELEMENTS |
8 | THE D- AND f-BLOCK ELEMENTS |
9 | CO-ORDINATION COMPOUNDS |
10 | HALOALKANES AND HALOARENES |
11 | ALCOHOLS, PHENOLS AND ETHERS |
12 | ALDEHYDES, KETONES AND CARBOXYLIC ACIDS |
13 | AMINES |
14 | BIOMOLECULES |
15 | POLYMERS |
16 | CHEMISTRY IN EVERYDAY LIFE |