Question

How much time is required for complete decomposition of two moles of water using 4 ampere

Answer 1

96500 seconds

Answer 2

The decomposition of 2 moles of water requires 4 moles of electrons. The total charge required is $Q = n_e \times F = 4 \text{ mol} \times 96500 \text{ C/mol} = 386000 \text{ C}$. The time required is $t = Q/I = 386000 \text{ C} / 4 \text{ A} = 96500 \text{ seconds}$.