AP EAPCET 19-Aug-2021 Shift 2 Paper

The unbalanced redox reaction is
MnO4−+C,O42−+H+→Mn2++CO2+H2O
(i) Balanced C atoms

+7

MnO4

+C2O42−+H+→Mn2++2CO2+H2O
Oxidation state of Mn decreases from +7 to +2.
To balance the increase or decrease in oxidation number, multiply Mn containing species with 2 and C containing species with 5.
2MnO4−+5C2O42−→2Mn2++10CO2
(ii) Balance ′O′ atoms by adding 8 water molecules to the product side.
2MnO4−+5C2O42−→2Mn2++10CO2+8H2O
(iii) Balance 'H' atoms by adding 16H+ions to the reactant side.
2MnO4−+5C2O42−+16H+→2Mn2++10CO2+8H2O
Hence, MnO4−⇒2C2O42−⇒5,H+=16