Zinc granules are added in excess to a 500 ml. of 1.0 M nickel nitrate solution at 25^oC until the equilibrium is reached. If the standard reduction potential of Zn²⁺ | Zn and Ni²⁺ | Ni are -0.75 V and -0.24 V respectively, find out the concentration of Ni²⁺ in solution at equilibrium.

The current of 1.70 A is passed through 300.0 ml of 0.160 M solution of a ZnSO₄ for 230 sec. with a current efficiency of 90%. Find out the molarity of Zn²⁺ after the deposition of Zn. Assume the volume of the solution to remain constant during electrolysis.

(i) What is the weight of sodium bromate and molarity pf solution necessary to prepare 85.5 ml of 0.672 B solution when the half-cell reaction is

$$BrO_3^- + 6H^+ + 6e^- \to $$ $$Br^- + 3H_2O$$

(ii) What would be the weight as well as molarity if the half-cell reaction is:

$$2BrO_3^- + 12H^+ + 10e^- \to$$ $$Br_2 \,+ 6H_2O$$