How many coulombs are required for the following reductions ?
(i) 1 mol of `Al^(3+)` to Al.
(ii) 1 mol of `Cu^(2+)` to Cu.

Answer

(i)`2.895xx10^(5) C, (ii)1.96xx10^(5) C`

Explanation

`(i)" " underset(1" mol")(Al^(3+))(aq)+3e^(-) to underset(2xx96500C)(Al(s))`
From the above equation,
The number of coulombs needed for the reduction of 1 mole of `Al^(3+)` ions
`=3xx96500" C "=2.895xx10^(5)C`.
`(ii)" " underset(1" mol")(Cu^(2+))(aq)+2e^(-) to underset(2xx96500C)(Cu(s))`
From the above equation,
The number of coulombs needed for the reduction of 1 mole of `Cu^(2+)` ions
`=2xx96500" C" =193000" C"=1.93xx10^(5)" C"`.