1.In the button cells widely used in watches and other devices the following reaction takes place:

Zn(s) + Ag_{2}O(s) + H_{2}O(*l *) ® Zn^{2+}(aq) + 2Ag(s) + 2OH^{–}(aq)

Determine Δ*rG *^{0 }and *E*^{0} for the reaction.

2.A solution of CuSO_{4} is electrolysed for 10 minutes with a current of 1.5 amperes. What is the mass of copper deposited at the cathode?

3.Resistance of a conductivity cell filled with 0.1 mol L^{–1} KCl solution is 100 W . If the resistance of the same cell when filled with 0.02 mol L^{–1} KCl solution is 520 W , calculate the conductivity and molar conductivity of 0.02 mol L^{–1} KCl solution. The conductivity of 0.1 mol L^{–1} KCl solution is 1.29 S/m.

4.If a current of 0.5 ampere flows through a metallic wire for 2 hours, then how many electrons would flow through the wire?

5.The conductivity of 0.20 M solution of KCl at 298 K is 0.0248 S cm^{–1}. Calculate its molar conductivity.

6.Calculate the potential of hydrogen electrode in contact with a solution whose pH is 10.

7.The conductivity of 0.001028 mol L^{–1} acetic acid is 4.95 × 10^{–5} S cm^{–1}. Calculate its dissociation constant if Λ^{0}_{m} for acetic acid is 390.5 S cm^{2} mol^{–1}.

8.The molar conductivity of 0.025 mol L^{–1} methanoic acid is 46.1 S cm^{2} mol^{–1}. Calculate its degree of dissociation and dissociation constant. Given l^{0}(H^{+}) = 349.6 S cm^{2} mol^{–1} and λ^{0 }(HCOO^{–}) = 54.6 S cm2 mol^{–1}.

9.Calculate the standard cell potentials of galvanic cell in which the following reactions take place: (i) 2Cr(s) + 3Cd^{2+(}aq) ® 2Cr^{3+}(aq) + 3Cd (ii) Fe^{2+}(aq) + Ag^{+}(aq) ® Fe^{3+}(aq) + Ag(s)

Calculate the DR*g*^{0 }and equilibrium constant of the reactions.

10.Conductivity of 0.00241 M acetic acid is 7.896 × 10^{–5} S cm^{–1}. Calculate its molar conductivity. If Λ^{0}_{m } for acetic acid is 390.5 S cm^{2} mol^{–1}, what is its dissociation constant?

11.Predict the products of electrolysis in each of the following:

(i) An aqueous solution of AgNO_{3} with platinum electrodes.

(ii) A dilute solution of H_{2}SO_{4} with platinum electrodes.

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