Question

Gallium is produced by the electrolysis of a solution obtained by dissolving gallium oxide in concentrated NaOH(aq). Calculate the amount of Ga(s) that can be deposited from a Ga(III) solution by a current of 0.520 A that flows for 30.0 min.

Answer 1

Electrolysis equation is:
Ga3+   +   3e-    ------> Ga

1 mol of Ga requires 3 mol of electron
1 mol of electron = 96485 C
So,1 mol of Ga requires 289455 C

let us calculate the charge passed:
t = 30.0 min = 30.0*60 s = 1800 s

time, t = 1800s

Q = I*t
= 0.52A * 1800s
= 936 C

mol of Ga plated = 936/289455 = 0.00323 mol
Molar mass of Ga = 69.72 g/mol

mass of Ga = number of mol * molar mass
= 0.00323 * 69.72
= 0.225 g
Answer: 0.225 g