question_answer

An impure sample of sodium oxalate \[(N{{a}_{2}}{{C}_{2}}{{O}_{4}})\]weighing 0.20 g is dissolved in aqueous solution of \[{{H}_{2}}S{{O}_{4}}\] and solution is titrated at \[70{}^\circ C\], requiring 45 mL of \[0.02\,M\,KMn{{O}_{4}}\] solution. The end point is overrun, and back titration in carried out with 10 mL of 0.1 M oxalic acid solution. Find the percentage purity of \[N{{a}_{2}}{{C}_{2}}{{O}_{4}}\] in sample.

Answer:

83.75