Question

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 $HCl$

• A. Oxidises oxalic acid to carbon dioxide and water
• B. Gets oxidised by oxalic acid to chlorine
• C. Furnishes $H^{+}$ ions in addition to those from oxalic acid
• D. Reduces permanaganate to $M{n}^{2+}$

Answer 1

The correct option is D Reduces permanaganate 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 $H_{2}S{O}_4$
$2KMn{O}_4+3H_{2}S{O}_4+5H_2{C}_2{O}_4\to K_{2}S{O}_4+2MnS{O}_4+10C{O}_2+5H_{2}O$
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 can not be determined.