Question:
Balance the following equations by the oxidation number method.
(i) Fe2+ + H+ + Cr2 O2-7→ Cr3+ + Fe3+ + H2O
(ii) I2+ N – O3 → NO2+ I – O3
(iii) I2 + S22– O3 → I– + S42– O
(iv) MnO2 + C2 O2-4→ Mn2+ + CO2
Solution:
(i) 6Fe2+ + Cr2O72- + 14H+ → 6Fe3+ + 2Cr3+ + 7H2O
(ii) I2 + 10NO3- + 8H+ → 2IO3- + 10NO2 +4H2O
(iii) 2S2O3 2- + I2 → S4O62- + 2l-
(iv) C2O402- +MnO2 + 4H+ → 2CO2 +MN2+ +2H2O