One mole of an equimolar mixture of ferric oxalate, , and ferrous oxalate, , required exactly moles — Redox Reactions and Volumetric Analysis Chemistry Question

💡 Solution & Explanation

1 mole of an equimolar mixture contains 0.5 moles of each. For $Fe_2(C_2O_4)_3$: $Fe^{3+}$ is already oxidized; 3 oxalate groups oxidize to $6CO_2$ losing 6e-. (n=6). Equivalents = $0.5 \times 6 = 3.0$. For $FeC_2O_4$: Fe loses 1e-, oxalate loses 2e-. (n=3). Equivalents = $0.5 \times 3 = 1.5$. Total equivalents = $3.0 + 1.5 = 4.5$. $KMnO_4$ in acidic medium has n=5. Equivalents = $5X$. So $5X = 4.5 \Rightarrow X = 0.9$. Therefore, $20X = 20 \times 0.9 = 18$.