Question

What happens when conc. sulphuric acid is added to active metals? Explain using a suitable reaction.

Answer 1

Hot, concentrated sulphuric acid oxidises active metals to form their metal sulphate and releases sulphur dioxide (SO₂) gas.

\[\ce{Zn + 2H2SO4 (conc.) ->[\Delta] ZnSO4 + 2H2O + SO2 ^}\]

A colourless gas with a suffocating, pungent smell of burning sulphur (SO₂) is evolved.