The approximate time duration in hours to electroplate 30 g of calcium from molten calcium chloride using a current of 5 amp is [At. Mass of Ca=40]

Options

A. 8
B. 80
C. 10
D. 16

Answer

A

Explanation

Q = it
`Ca^(2+) (aq) + 2e^(-) to Ca(s)`
`2 xx 96500 C` charges required to deposit 40 g Ca 40 g Ca deposited by `2 xx 96500 C` changes
1g Ca deposited by `(2 xx 96500)/40`
and 30 g Ca deposited by `(2 xx 96500)/40 xx 30`
`96500 xx 3/2 C` charges
Q = it
`t = Q/I`
`= 96500 xx 3/2 xx 1/5`
8 hours