Amount of oxalic acid present in a solution can be determined by its titration with $KMn{O}_4$ solution in the presence of $H_{2}S{O}_4$. The titration gives unsatisfactory result when carried out in the presence of $HCl$, because $HCl$:

The correct option is D Reduces permanganate to $M{n}^{2+}$
Oxalic acid present in a solution can be determined by its titration with $KMn{O}_4$ solution in the presence of $H_{2}S{O}_4$.


Titration cannot be done in the presence of $HCl$ because $KMn{O}_4$ being a strong oxidizing agent oxidises $HCl$ to $C{l}_2$ and get itself reduced to $M{n}^{2+}$. So actual amount of oxalic acid in solution cannot be determined.