(2)
Mn2(SO4)7 ⇄ 2 Mn7+ + 7 SO42−
(3)
2 Mn7+ + 7 SO42− + 10 Fe2+ + 10 SO42−
⇄ 2 Mn2+ + 1 OFe3+ + 17 SO42−
(4)
⇄ 2 MnSO4 + 5 Fe2(SO4)3
(5)
Analogous results are obtained with potassium chromate or dichromate against potassium iodide, ferrous sulphate, hydrogen sulphide, and other reducing agents.
Nitric Acid.
H+ + NO3− ⇄ (HO)NO2
(HO)NO2 + 2 HOH ⇄ N(OH)5 ⥃ N5+ + 5 HO−