Question

During oxidation of ferrous sulphate using mixture of dill. H2SO4 and potassium dichromate; oxidation state of chromium change form

Answer 1

The oxidising agent used in these reactions is normally a solution of sodium or potassium dichromate(VI) acidified with dilute sulphuric acid. If oxidation occurs, the orange solution containing the dichromate(VI) ions is reduced to a green solution containing chromium(III) ions

Answer 2

During oxidation of ferrous sulfate using mixture of dil. H2SO4 and potassium dichromate, the oxidation state of chromium change form (+6) in potassium dichromate to (+3) in chromium(III) ion.

• Ferrous sulfate is oxidized to ferric sulfate,i.e the oxidation state of iron changes from (2) to (3).
• Dil. H2SO4 provides an acidic medium for the reaction to proceed.
• Potassium dichromate acts as an oxidizing agent and haence is reduced to Chromium(III) ions which renders the resulting solution its green colour.