The correct option is
B 66% Reaction taking between potassium permanganate and axalate-
MnO−4+C2O2−4+H+→Mn2++CO2+H2O
Hence equivalent of KMnO4 oxidizes 2.5 equivalences of axalate
Moles of KMnO4=0.05×0.095=9×10−4.....(1)
Moles of oxalate that MKnO4 axidizes =9×10−4×2.5
=22.5×10−4 (from (1))......(2)
Molecolar weight of oxalate =2×12+4×16=88
(∵C2O4, where C=12 & O=16)......(3)
Oxalate ion amount =22.5×10−4×88=0.198 from (2) & (3)
Percentage of oxalate ion =0.198×1000.3=66%
Ans B) 66%