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_(Au^(+3)//Au)^(@)=1.50,E_(Li^(+)//Li)^(@)=-3.03V`
will increasing voltage, the sequence of deposition of metals on the cathode will be `:`

Options

A. Li , Cu , Ag , Au
B. Cu , Ag , Au
C. Au , Ag , Cu
D. Au , Ag , Cu , Li

Answer

C

Explanation

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