Question

The oxidation states of the metal in the minerals haematite and magnetite respectively are:

• A. II, III in haematite and III in magnetite
• B. II, III in haematite and II in magnetite
• C. III in haematite and II, III in magnetite
• D. II in haematite and II, III in magnetite

Answer 1

The correct option is C III in haematite and II, III in magnetite

Haematite is ($F{e}_2{O}_3$). Let the oxidation state of $Fe$ be x
i.e 2x - 6 = 0
x = 3
Magnetite is ($F{e}_3{O}_4$). It is the oxide of $Fe$ which exist as ($FeO.F{e}_2{O}_3)$.
Hence, $Fe$ exists in both +2 and +3 oxidation state.