Q11 / 180 · COMEDK 2022 · Chemistry
$\mathrm{KMnO}_4$ acts as an oxidising agent in acidic medium. The number of moles of $\mathrm{KMnO}_4$ that will be required to react with one mole of oxalate ions (to form $\mathrm{CO}_2$ ) in acidic solution is
- Correct answerA$\dfrac{2}{5}$
- B$\dfrac{5}{2}$
- C5
- D$\dfrac{5}{4}$
Solution
The balanced chemical equation for the reaction between permanganate ions and oxalate ions in an acidic medium is given by:
$2\mathrm{MnO}_{4}^{-} + 5\mathrm{C}_{2}\mathrm{O}_{4}^{2-} + 16\mathrm{H}^{+} \rightarrow 2\mathrm{Mn}^{2+} + 10\mathrm{CO}_{2} + 8\mathrm{H}_{2}\mathrm{O}$
From the stoichiometry of the balanced equation, $2$ moles of $\mathrm{MnO}_{4}^{-}$ react with $5$ moles of $\mathrm{C}_{2}\mathrm{O}_{4}^{2-}$.
Therefore, the number of moles of $\mathrm{MnO}_{4}^{-}$ required to react with $1$ mole of $\mathrm{C}_{2}\mathrm{O}_{4}^{2-}$ is $\dfrac{2}{5}$ moles.
Answer: $\dfrac{2}{5}$
$2\mathrm{MnO}_{4}^{-} + 5\mathrm{C}_{2}\mathrm{O}_{4}^{2-} + 16\mathrm{H}^{+} \rightarrow 2\mathrm{Mn}^{2+} + 10\mathrm{CO}_{2} + 8\mathrm{H}_{2}\mathrm{O}$
From the stoichiometry of the balanced equation, $2$ moles of $\mathrm{MnO}_{4}^{-}$ react with $5$ moles of $\mathrm{C}_{2}\mathrm{O}_{4}^{2-}$.
Therefore, the number of moles of $\mathrm{MnO}_{4}^{-}$ required to react with $1$ mole of $\mathrm{C}_{2}\mathrm{O}_{4}^{2-}$ is $\dfrac{2}{5}$ moles.
Answer: $\dfrac{2}{5}$
Hence, the correct answer is option: 'A'.