Three electrolytic cell `A,B`, and `C` contaning solutions of `ZnSO_(4), AgNO_(3)`, and `CuSO_(4)`, respectively, are connected in series. A steady current of `1.5A` was passed through them until `1.45 g` of silver deposited at the cathode of cell `B`. How long did the current flow ? What mass of copper and zinc were deposited ?

Explanation

`Ag^(+)+e^(-)rarr Ag(s)`
108 g of silver is deposited by 96500 C.
`"1.45 g silver is deposited by"=(96500xx1.45)/(108)`
`=1295.6C`
`Q=Ixxt`
`1295.6=1.5xxt`
`t=(12956)/(1.5)=863s`
In cell A, the electrode reaction is 5.6
`Zn^(2+)+2e^(-)rarr Zn`
2F of electricity deposit Zn = 65.3 g
`"1295.6 of electricity deposit Zn"=(65.3xx1295.6)/(2xx96500)`
`=0.438g`
In cell C, the electrode reaction is
`Cu^(2+)+2e^(-)rarrCu(s)`
2F of electricity deposit Cu = 63.5 g
`"1295.6 of electricity deposit Cu"=(63.5xx1295.6)/(2xx96500)`
`=0.426g`