Copper is heated with concentrated sulphuric acid: Cu + 2H2SO4 -> CuSO4 + SO2 + 2H2O. For every mole of Cu dissolved, the number of moles of H2SO4 acting as the oxidising agent is

JEE Main levelSingle correct optionDifficulty 2 of 3pn078

Copper is heated with concentrated sulphuric acid: $Cu + 2 H X_{2} SO X_{4} CuSO X_{4} + SO X_{2} + 2 H X_{2} O$ . For every mole of Cu dissolved, the number of moles of $H X_{2} SO X_{4}$ acting as the oxidising agent is

Of the 2 mol of

H X_{2} SO X_{4}

consumed, 1 mol is reduced to

SO X_{2}

(S from +6 to +4, gaining 2 electrons as Cu loses 2), while the other mole only supplies sulphate for

CuSO X_{4}

. So 1 mol acts as the oxidant.