What is the equivalent mass of (Molar mass = M) in the basic disproportionation reaction ? — Redox Reactions and Volumetric Analysis Chemistry Question

💡 Solution & Explanation

Disproportionation of $I_2$ (0) to $I^-$ (-1) and $IO_3^-$ (+5). Oxidation half: $I_2 \rightarrow 2IO_3^- + 10e^-$ ($n_1 = 10$). Reduction half: $I_2 + 2e^- \rightarrow 2I^-$ ($n_2 = 2$). Equivalent weight $E = M/10 + M/2 = (M + 5M)/10 = 6M/10 = 3M/5$.