Electrochemistry

Electrochemistry
Class:XII / Unit:3

In Galvanic cell, current flows from

Anode to cathode
Cathode to anode
Either electrode
None of these

During the electrolysis of molten NaCl, at anode

Sodium is liberated
Oxygen is liberated
Chlorine is liberated
NaCl is liberated

If 96500 coulomb of electricity is passed through CuSO4 solution, it will liberate

63.5 grams of Cu
31.76 grams of Cu
1 gm Cu
100 grams of Cu

Complete cell reaction of Galvanic cell is

Zn⁺² + Cu -----> Cu⁺² + Zn
Zn + Cu⁺² -----> Zn⁺² + Cu
Zn + Cu⁺ -----> Zn⁺ + Cu
Zn + Cu -----> Zn⁺² + Cu⁺²

The potential of a hydrogen electrode at pH = 10 is:

–0.59 V
0.59 V
10.00 V
–0.059 V

The standard EMF of Daniell cell is 1.10 volt. The maximum electrical work obtained from the Daniell cell is

53.07 kJ
106.15 kJ
175.4 kJ
212.3 kJ

The reduction potential values of X, Y and Z are -3.05 V, -0.44 V and -0.83 V respectively. Which of the following order is correct with respect to their reducing property

Z > Y > X
X > Z > Y
Y > Z > X
X > Y > Z

Hydrogen gas is not liberated when the following metal is added to dil. HCl

Sn
Ag
Mg
Zn

Corrosion of iron is essentially an electrochemical phenomenon where the cell reaction are

Fe is oxidised to Fe²⁺ and H₂O is reduced to O_2^-
Fe is oxidised to Fe²⁺ and H₂O is reduced to O₂
Fe is oxidised to Fe³⁺ and H₂O is reduced to O_2^-2
Fe is oxidised to Fe²⁺ and H₂O is reduced to OH^–

In a cell that utilizes the reaction Zn(s) + 2H⁺(aq) ---> Zn⁺² (aq) + H₂(g) addition of H₂SO₄ to cathode compartment, will

increase the E and shift the equilibrium to the right
increase the E and shift the equilibrium to the left
lower the E and shift the equilibrium to the right
lower the E and shift equilibrium to the left