Amount of oxalic acid present in a solution can be determined by its titration with KMnO4 solution in the presence of H2SO4. The titration gives unsatisfactory result when carried out in the presence of HCl, because HCl
gets oxidised by oxalic acid to chlorine
furnishes H+ions in addition to those from oxalic acid
reduces permanganate to Mn2+
oxidises oxalic acid to carbon dioxide and water
C.
reduces permanganate to Mn2+
HCl being stronger reducing agent reduces MnO4− to Mn2+ and result of the titration becomes unsatisfactory.
