Acic base + Redox titration 1^(st)titration : M/10 reacts with oxalic acid as well as H_(2)SO_4according to equation H_(2)C_(2)O_4 + NaOH rarrNa_(2)C_(2)O_4 + H_(2)O, H_(2)SO_(4) + NaOH rarr Na_(2)SO_(4) + H_(2)O 2^(nd)titration : The mixture solution is titrated with M/10KMnO_4 solution which will reacts with oxalic acid (redox titration) in the presence of H_(2)SO_(4) H_(2)C_(2)O_(4) + underset(("Purple"))(KMnO_4)+H_(2)SO_(4) rarr K_(2)SO_(4) +underset(("Colourless"))( MnSO_4)+H_2O+CO_2 The reactionof oxalic acid with KMnO_4is very slow therefore the oxalic acid solution is heated to 60-70^@Cinitially. Once the reation has started, its rate automatically increases. MnO_4^(-)acts as an oxidising agent. MnO_(4)^(-)overset(H^(+))rarrunderset("colourless")(Mn^(++),MnO_(4)^(--),MnO_(4) underset(H_2O)rarroverset("Brown ppt")(MnO_2) In the permanganate titration, the solution of reductant is always made acidic by adding H_2SO_4rather than HCl or HNO_3because