Chromium metal can be plated out from an acidic solution containing `CrO_(3)` according to the following equation `:`
`CrO_(3)(aq)+6H^(o+)+6H^(o+)(aq)+6e^(-) rarr Cr(s)+3H_(2)O`
`a.` How many grams of chromium will be plated out by `24000C` ?
`b.` How long will take to plate out `1.5g` of chromium by using `12.5 A` current ?

Explanation

We Know,
Eq. `wt.` of `Cr = ("At. Wt.")/("No. of electrons lost or gained by one molecule of Cr") = (52)/(6)`
(i) `:' 96500` coulomb deposit `= 52/(6)g Cr`
`:. 24000` coulomb dedposit `= (52)/(6) xx (24000)/(96500)`
`2.1554 g` of `Cr`
(ii) Also given, `w_Cr = 1.5 g, i = 12.5` ampere,
`t = ? E_(Cr) = 52//6`
`w= (E.i.T)/(965000)` ltbRgt `1.5 = (52 xx 12.5 xx t)/(6 xx 96500)`
`t = 1336.15` second