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 2 Hg^(2+)|Hg=+0.79`
`Cu^(2+)|Cu=+0.34 Mg^(2+)|Mg=-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, more easily is the metal deposited `(M^(n+)+n e^(-)toM)`. `Mg^(2+)` ions will not be deposited because `H_(2)O` is reduced more easily than `Mg^(2+)` ions.