$\mathrm{MnO}_4^{-}$ions are reduced in acidic condition to $\mathrm{Mn}^{2+}$ ions whereas they are

Question

$\mathrm{MnO}_4^{-}$ions are reduced in acidic condition to $\mathrm{Mn}^{2+}$ ions whereas they are reduced in neutral condition to $\mathrm{MnO}_2$. The oxidation of 25 mL of a solution $X$ containing $\mathrm{Fe}^{2+}$ ions required in acidic condition 20 mL of a solution $Y$ containing $\mathrm{MnO}_4^{-}$ ions. What volume of solution $Y$ would be required to oxidise 25 mL of solution $X$ containing $\mathrm{Fe}^{2+}$ ions in neutral condition?

Professor PC Thomas Classes · Answer

(c) In acidic medium, \ $ \frac{M_1 V_1}{1}=\frac{M_2 V_2}{5} \Rightarrow \frac{M_1 	imes 20}{1} \ =\frac{M_2 	imes 25}{5}, M_1=\frac{M_2}{4} \ $ In neutral medium, $ \ \frac{M_1 V_1}{1}=\frac{M_2 V_2}{3} \Rightarrow \frac{M_2 	imes V_1}{4}\ =\frac{M_2 	imes 25}{3}, V_1=33.3 \mathrm{~mL} $