Answer: 0.256 g
Explanation:
The deposition of Ga from Ga(III) solution

According to mole concept:
1 mole of an atom contains
number of particles.
We know that:
Charge on 1 electron = 
Charge on 1 mole of electrons = 

where,
I = current passed = 0.590 A
q = total charge = ?
t = time required = 30.0 min = 1800 s (1min=60s)
Putting values in above equation, we get:


will deposit = 70 g of Gallium
will deposit =
of Gallium
Thus 0.256 g of Ga(s) that can be deposited from a Ga(III) solution using a current of 0.590 A that flows for 30.0 min.