How many of the following elements undergo disproportionation when reacted with an alkaline () mediu — Redox Reactions and Volumetric Analysis Chemistry Question

💡 Solution & Explanation

Chlorine ($Cl_2 \rightarrow Cl^- + ClO^-/ClO_3^-$), Phosphorus ($P_4 \rightarrow PH_3 + H_2PO_2^-$), Sulphur ($S_8 \rightarrow S^{2-} + S_2O_3^{2-}$), and Iodine all undergo disproportionation in alkali. Fluorine ($F_2$) is an exception; as the most electronegative element, it only gets reduced (to $F^-$) and never oxidized. Total = 4.