Question

What happens when sulphur dioxide is passed through an aqueous solution of Fe(III) salt?

Answer 1

SO2 acts as a reducing agent when passed through an aqueous solution containing Fe(III) salt. It reduces Fe(III) to Fe(II) i.e., ferric ions to ferrous ions.
`2Fe^(3+)+ SO_(2)+ 2H_(2)O to 2 Fe^(2+) + SO_(4)^(2-)+ 4 H^(+)`