Ferrous sulphate is treated with potassium permanganate in the presence of suphuric acid. Potassium sulphate, manganese sulphate, ferric sulphate are the products of the reaction. The number of moles of sulphuric acid required for 1 mole of $$\text{KMnO}_4$$ ____.

The balanced equation is $$10\text{FeSO}_4 + 2\text{KMnO}_4 + 8\text{H}_2\text{SO}_4 \rightarrow \text{K}_2\text{SO}_4 + 2\text{MnSO}_4 + 5\text{Fe}_2(\text{SO}_4)_3 + 8\text{H}_2\text{O}$$. So 2 mol of $$\text{KMnO}_4$$ need 8 mol of $$\text{H}_2\text{SO}_4$$, i.e. 4 mol for each mole of $$\text{KMnO}_4$$.