The equivalent weight of orthophosphoric acid ( , Molar mass = M) in the reaction is: — Redox Reactions and Volumetric Analysis Chemistry Question

💡 Solution & Explanation

The equivalent weight of an acid depends on the number of replaceable hydrogen atoms (basicity) utilized in the specific reaction. Here, $H_3PO_4$ loses two of its three protons to form $HPO_4^{2-}$ . Thus, its utilized basicity (n-factor) is 2, making its equivalent weight M/2.