Question

If mercury is used as cathode in the electrolysis of aqueous NaCl solution, the ions discharged at cathode are:

• A. H${}^{+}$
• B. Na${}^{+}$
• C. OH${}^{-}$
• D. Cl${}^{-}$

Answer 1

Answer: (B)

Na${}^{+}$

In presence of Hg electrode, sodium ions are discharged in the form of a mercury sodium amalgam and chloride ions are converted to chlorine.
So, $N{a}^{+}$ ions discharged at cathode.