(a)
Given, $i = 2.5A$
$t\ = \ 6\ \min\ 26\ s = 6 \times 60 + 26 = 386s$
Number of coulomb passed $= \ i\ \times \ t$
$= 2.5\ \times \ 386\ \ \$
$\ \ \ \ \ \ \ \ = \ \ 965\ C$
$\ \ \ {Cu}^{2 +} + \ {2e}^{-}\ \longrightarrow Cu$
∴ $2\ \times \ 96500\ C\ charge\ deposits\ Cu\ = \ 63.5\ g$
∴ 965 C charge deposits
$Cu\ = \ \frac{63.5}{2\ \times 96500}\ \times 965\$
= 0.3175 g