Question

A solution of Ni(NO₃)₂ is electrolyzed between platinum electrodes using a current of 5 amperes for 20 min. What mass of Ni is deposited at the cathode ? (Atomic mass of Ni = 58.7)

[Report your answer by rounding it upto nearset whole number]

Answer 1

Answer: 2

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 :



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 10⁵ C

Molar mass of nickel = 58.7g mol^-1

1.93 x 10⁵ C of charge produces nickel = 58.7g

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

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