Calculate the time required to coat a metal surface of `80 cm^(2)` with `0.005 mm` thick layer of silver (density `= 10.5 g cm^(3))` with the passage of `3A` current through silver nitrate solution.

Explanation

`:'` Volume of layer of silver `= 0.005 xx 10^(-1) xx 80 = 0.04 cm^(3)`
`:.` Mass = Density `xx` volume `=10.5 xx 0.04 = 0.42 g`
So `w = (E)/(96500) xx It rArr 0.42 = (108)/(96500) xx 3xx t`
`t = (0.42 xx 96500)/(108 xx 3) = 125.09` seconds.
b. Faraday's second law: This law states that the amounts of different substance deposited in different solutions connected in series at elecrodes by passage of the same quantity of electricity are proportional to their equivalent masses `(E)`.