In which of the following reactions does the equivalent weight of the given reactant exactly equal i — Redox Reactions and Volumetric Analysis Chemistry Question

💡 Solution & Explanation

$Fe^{2+}$ loses 1e- (n=1). $KMnO_4$ in strong base reduces to Manganate (+7 to +6, n=1). $Na_2S_2O_3$ oxidizes to tetrathionate (n=1 per mole of thiosulphate as 2 moles lose 2e-). $H_3PO_2$ is a monobasic acid, neutralizing exactly 1 $OH^-$ (n=1).