In the disproportionation reaction , what is the equivalent weight (E) of (Molar mass = M)? — Redox Reactions and Volumetric Analysis Chemistry Question

💡 Solution & Explanation

P in $H_3PO_2$ is +1. In $PH_3$, it is -3 (reduction n-factor $n_1 = 4$). In $H_3PO_3$, it is +3 (oxidation n-factor $n_2 = 2$). Equivalent weight in disproportionation is the sum of equivalent weights for both halves: $E = M/n_1 + M/n_2 = M/4 + M/2 = 3M/4$.