BITSAT 2024 Shift 1 Paper

Oxidation half reaction:
SO2(g)+2H2O(l)→HSO4−(aq)+3H+(aq)+2e−
Reduction half reaction:
MnO4−(aq)+8H++5e−→Mn2+(aq)+4H2O(l)
Multiply eq. (i) by 5 and (ii) by 2 and then add
2MnO4−(aq)+5SO2(g)+2H2O(l)+H+(aq)→2Mn+(aq)+5HSO4−(aq)
Thus, the stoichiometric coefficient of SO2 in the above balance equation is 5 .