Question

What happens when ethanol is heated at 443K in the presence of conc. H₂SO₄? Write the role of conc. H₂SO₄ in this case.

Answer 1

Reaction to give unsaturated hydrocarbon: Heating ethanol at 443 K with excess concentrated sulphuric acid results in the dehydration of ethanol to give ethene –

\[\ce{CH3-CH2OH  ->[Hot Conc{.}][443K H2SO4]CH2 = CH2 + H2O}\]

The concentrated sulphuric acid can be regarded as a dehydrating agent which removes water from ethanol.