Copper sulphate solution (250 mL) was electrolysed using platinum anode and a copper cathode. A constant current of 2mA was passed for 16 minutes. It was found that after electrolysis the absorbance of the solution was reduced to 50% of its original value. Calculate the concentration of copper sulphate in the solution to begin with.

The following electrochemical cell has been set up.
Pt(1) | Fe³⁺, Fe²⁺ (a = 1) | Ce⁴⁺, Ce³⁺ (a=1) | Pt(2)
E^o (Fe³⁺, Fe²⁺) = 0.77 V; E^o (Ce⁴⁺, Ce³⁺) = 1.61 V
If an ammeter is connected between the two platinum electrodes, predict the direction of flow of current. Will the current increase or decrease with time?

A cell, Ag | Ag⁺ || Cu²⁺ | Cu, initially contains 1 M Ag⁺ and 1 M Cu²⁺ ions. Calculate the change in the cell potential after the passage of 9.65 A current for 1 h.

Calculate the equilibrium constant for the reaction:
2Fe³⁺ + 3I^- $$\leftrightharpoons$$ 2Fe²⁺ + $$I_3^-$$. The standard reduction potentials in acidic conditions are 0.78 V and 0.54 V respectively for Fe³⁺ | Fe²⁺ and $$I_3^-$$ | I^- couples.