In electrolysis of `NaCl` when `Pt` electrode is taken `H_(2)` is liberated at cathode while `Hg` cathode it forms sodium amalgam because

Options

A. Hg is more inert than Pt
B. more voltage is required to reduce `H^(+)` at Hg than at Pt
C. Na is dissolved in Hg while it does not dissove in Pt
D. concentration of `H^(+)` ions is larger when Pt electrode is taken

Answer

D

Explanation

Voltage required to reduce ions changes with the nature of electrode. No `H_(2)` gas is liberated as more voltage is required to reduce `H^(+)` at Hg than at Pt.