Amount of oxalic and present in a solution can be determined by its nitration with $kM_nO_4$ solution in the presence of $H_2SO_4$ . The nitration gives unsatisfactory result when carried out in the presence of Hcl because Hcl

Question

$\begin{array}{1 1} \text{reduces permanganate to} Mn^{2+} \\\text{Oxidises oxalic acid to carbon dioxide and water} \\ \text{gets oxidized by oxalic acid to chlorine} \\\text{furnishes $H^+$ ions in addition to those from oxalic acid } \end{array}$