15 mLN20KMnO4=10× Normality of oxalate solution.
Normality of oxalate solution =1520×120=340
Strength of oxalate solution =Normality× Eq. mass of oxalate
=340×44=3.3 g/L [Eq. mass of C2O2−4=882=44]
Amount of oxalate in 100 mL solution =3.31000×100=0.33 g
% of oxalate =0.330.5×100=66.0