What is the equivalent weight of the complex polyprotic salt potassium tetroxalate, , when it acts e — Redox Reactions and Volumetric Analysis Chemistry Question

💡 Solution & Explanation

The complex salt contains one oxalate ion originating from $K_2C_2O_4$ and three oxalate ions originating from $3H_2C_2O_4$ , giving a total of 4 moles of $C_2O_4^{2-}$ ions per mole of the bulk salt. During a redox titration with $KMnO_4$ , each $C_2O_4^{2-}$ ion undergoes complete oxidation to $2CO_2$ , losing 2 electrons. The total number of electrons lost per mole of the salt is $4 \times 2 = 8$ . Therefore, its redox n-factor is 8, making its equivalent weight $M/8$ .