What exact volume of a standard solution is mathematically required to completely oxidize of a solut — Mole Concept and Some Basic Concepts of Chemistry Chemistry Question
Question
What exact volume of a standard $0.1\text{ M } KMnO_4$ solution is mathematically required to completely oxidize $100\text{ mL}$ of a $0.2\text{ M } FeSO_4$ solution in a strongly acidic medium?
💡 Solution & Explanation
Step 1: Determine the n-factor for both reagents. In an acidic medium, $KMnO_4$ is reduced to $Mn^{2+}$, meaning a change in oxidation state of 5 (n-factor = 5). For $FeSO_4$, $Fe^{2+}$ oxidizes to $Fe^{3+}$, meaning a change in oxidation state of 1 (n-factor = 1). Step 2: Calculate the normalities. Normality of $KMnO_4 = 0.1 \times 5 = 0.5\text{ N}$. Normality of $FeSO_4 = 0.2 \times 1 = 0.2\text{ N}$. Step 3: Apply the Law of Equivalence. $(N_1V_1)_{\text{oxidant}} = (N_2V_2)_{\text{reductant}}$. $0.5 \times V_1 = 0.2 \times 100 \Rightarrow 0.5 \times V_1 = 20 \Rightarrow V_1 = 40\text{ mL}$.