An aqueous solution containing one mole per litre of each `Cu(NO_(3))_(2), AgNO_(3),Hg(NO_(3))_(2)` is being electrolysed using inert electrodes. The values of standard electrdoe potential in volts (reduction potential) are
`Ag|Ag^(+)=+0.80 2Hg|Hg^(2+)=+0.79`
`Cu|Cu^(2+)=+0.34 Mg|Mg^(2+)=-2.37`
With increasing voltage, the sequence of deposition of metals on cathode will be

Options

A. `Ag,Hg,Cu,Mg`
B. `Mg,Cu,Hg,Ag`
C. `Ag,Hg,Cu`
D. `Cu,Hg,Ag`

Answer

C

Explanation

Higher the reduction potential easier to reduce. From an aqueous situation Mg cannot be obtained by electrolysis. Therefore, correct order of depositions as voltage is increased is Ag,Hg, Cu.