Question

What weight of Ni is plated out in an electrolysis of aqueous ${NiSO}_4$ solution that it takes place to deposit 2g of Ag in a silver coulometer that is arranged in series with ${NiSO}_4$ electrolytic cell.[atomic weight of Ag=107.8 amu,atomic weight of Ni=58.7 amu]

Answer 1

$\underset{Ni}{\underset{}{\frac{W_1}{Z_1}}}=\underset{Ag}{\underset{}{\frac{W_2}{Z_2}}}$ (for series)

$\therefore W_1=z_1\left(\frac{2}{107.8/1}\right)$$=\left(\frac{58.7}{2}\right)$$\times \left(\frac{2}{107.8}\right)$$=0.54g.$

$Note:\left\{\begin{array}{c}{n}_f\left({Ni}^{2+}\right)=2\\ n_f\left({Ag}^{+}\right)=1\end{array}\right\}$