The number of moles of KMnO4 that will be needed to react completely with one mole of ferrous oxalate in acidic solution is

KMnO4 :   n-factor in acidic medium =5                     FeC2O4  :     n-factor = 3              MnO4-→Mn+2Fe+2→Fe+3;C2O4-2→2CO2 criss-cross method3 moles of KMnO4  oxidizes 5 moles of FeC2O4 X moles of KMnO4  oxidizes 1 moles of FeC2O4    X = 3/5