The time required to deposit 90 g of Al from an electrolytic cell containing `Al_(2)O_(3) ` by a current of 965 A (At.mass of Al = 27)

Options

A. 20 min . 20 sec
B. 16 min . 40 sec
C. 40 min 20 sec
D. 26 min

Answer

B

Explanation

W = 90 gm , i= 965 A , t = ? W = Zit `therefore t = (W)/(Zi)`
`Z = ("Eq. mass")/(96500)`
for Al , Eq. mass `= (27)/(3) therefore Z = (27)/(3 xx 96500)`
`t = (90 xx 3 xx 96500)/(27 xx 965) = 1000` sec = 16 min . 40 sec