Oxidation of KMnO4 takes place in all the three medium acidic, basic and neutral. In all three medium the oxidation number is different. In acidic medium 2KMnO4+3H2SO4────▸K2SO4+2MnSO4+3H2O+5O The net reaction is MnO4−────▸Mn2+ Change in oxidation numbers =7−2=5 So, electrons involved =5e− In basic medium 2KMnO4+2KOH────▸2K2MnO4+H2O+O The net reaction is
+7
MnO4−
────▸
+6
MnO4−2
Change in oxidation numbers =7−6=+1 So, electrons involved =1e− In neutral medium 2KMnO4+H2O────▸2KOH+2MnO2+30 net reaction is MnO4−────▸MnO2 Change in oxidation numbers =7−4=+3 So, electrons involved =3e−