Question

What property of conc. H₂SO₄ is used in the action when sugar turns black in its presence?

Answer 1

H₂SO₄ is a dehydrating agent.

\[\ce{\underset{sulphide}{\underset{Sodium}{Na2S}} + \underset{sulphuric acid}{\underset{Dilute}{H2SO4}} -> \underset{sulphide}{\underset{Hydrogen}{H2S}} + \underset{sulphate}{\underset{Sodium}{Na2SO4}}}\]