In electrolysis of NaCl when Pt electrode is taken then $H_2$ is liberated at cathode while with Hg cathode it forms sodium amalgam : -

Question

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