Assertion : For drying H2S, Conc. H2SO4 cannot be used.
Reason: Moist H2S is oxidized by Conc.H2SO4
The correct option is
Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
Conc.H2SO4 Due to its strong affinity for water concentrated acid acts as a powerful dehydrating agent. Its corrosive action on the skin is due to this property.
Drying of gases: Many wet gases like carbon dioxide, sulphur dioxide, chlorine,
hydrogen chloride, etc. which have no action with acid, are dried by bubbling into the
concentrated sulphuric acid.
Moist hydrogen cannot be dried over conc.H2SO4 because it is oxidized by H2SO4 and catches fire.