Question

An aqueous solution containing `1M` each of `Au^(3+),Cu^(2+),Ag^(+),Li^(+)` is being electrolysed by using inert electrodes. The value of standard potentials are `:`
`E_(Ag^(+)//Ag)^(@)=0.80 V,E_(Cu^(+)//Cu)^(@)=0.34V` and `E_(Ag^(+3)//Au)^(@)=1.50,E_(Li^(+)//Li)^(@)=-3.03V`
will increasing voltage, the sequence of deposition of metals on the cathode will be `:`
A. `Li,Cu,Ag,Au`
B. `Cu,Ag,Au`
C. `Au,Ag,Cu`
D. `Au,Ag,Cu,Li`

Answer 1

Correct Answer - 3
Only `Au^(+3),Ag^(+)` and `Cu^(2+)` will deposit at cathode.
Li will not deposit at cathode because SRP of water is `-0.8274V` so after `Cu^(2+),H_(2)` will evolve at cathode.