In Dow's method, sodium is prepared by the electrolysis of molten NaCl. The reaction at the cathode is :
(a) Following reactions occur at cathode during the electrolysis of aqueous sodium chloride solution:
Na+(aq)+e−→Na(s) E∘=−2.71V H+(aq)+e−→12H2(g)E∘=0.00V
On the basis of their standard reduction electrode potential (E∘) values, which reaction is feasible at the cathode and why?
(b) Why does the cell potential of mercury cell remain constant throughout its life?