A solution containing one mole per litre of each `Cu(NO_(3))_(2), AgNO_(3), Hg_(2)(NO_(3))_(2)` is being electrolysed by using inert electrodes. The values of standard electrode potentials in volts (reduction potentials) are
`Ag^(+)//Ag = +0.80 V, HG_(2)^(2+)//Hg = +0.79 V`
`Cu^(+)//Cu = +0.34 V, Mg^(2+)//Mg = -2.37 V`
With increasing valtage, the sequence of deposition of metals on the 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

Mg cannot be obtained by electrolysing the aqueous salt solutions . Also `E_(OP)^(@)` order suggests for Ag , Hg , Cu.