Chromium is plated from a solution containing $Cr X^{3 +}$ using a current of $1.25 A$ . Find the time in minutes (nearest integer) needed to deposit $1.50 g$ of chromium at 100% efficiency. Take Cr = 52, $F = 96500 C mo l^{- 1}$ .

Numerical answer type, answer in min, tolerance 1.

Answer: 111 min

Moles of Cr

= 1.50/52 = 0.02885 mol

; electrons required

= 3 \times 0.02885 = 0.08654 mol

. Charge

Q = 0.08654 \times 96500 = 8351 C

. Time

t = Q / I = 8351/1.25 = 6681 s = 111.3 min \approx 111 min