Chemistry - Electrochemistry Question with Solution | TestHub

Quantity of electricity used = Current in amperes x Time in second = 5A x (20 x 60) s = 6000 C

Chemical equation for the reaction during electrolysis :

$\begin{array}{ccccccc}\text{Ni}{\left({\text{NO}}_3\right)}_2\left(\text{aq}\right)+2{\text{H}}^{+}& +& 2{\text{e}}^{-}& ⟶& \text{Ni}& +& 2{\text{HNO}}_3\\ & & 2\text{F}& & 58\text{.}7\text{g}& & \end{array}$

Charge Q on n moles of electrons is given by : Q = nF

Charge required to deposit 1 mole nickel

= 2 F = 2 x 96500 C = 1.93 x 10⁵C

Molar mass of nickel = 58.7g mol^-1

1.93 x 10⁵C of charge produces nickel = 58.7g

6000 C of charge produces nickel$=\frac{\left(58\text{.}\mathrm{7 }\text{g}\right)\times \left(600\mathrm{0 }\text{C}\right)}{\left(1\text{.}93\times 10^5\text{ C}\right)}$

$=1\text{.}82\text{ g}$