Question

How long would it take to deposit 50 g of Al from an electrolytic cell containing $Al_{2}O_{3}$ using a current of 105 ampere?

• A. $1.54h$
• B. $1.42h$
• C. $1.32h$
• D. $2.15$

Answer 1

Answer: (B)

$1.42h$

Answer 2

$Al^{3 +} + 3e^{-} \rightarrow Al$

Eq. wt. of Al $= \frac{27}{3} = 9$

W = Z ×I ×t

$Z = \frac{Eq.wt.}{96500}$

$t = \frac{W \times 96500}{Eq.wt. \times I} = \frac{50 \times 96500}{9 \times 105} = 5105.82s$ or $1.42H$