Question

Which one of the following compounds does not exhibit a different oxidation number of the same element ?
(a) Pb₂O4
(b) Fe,04
(c) Fe₂O₃
(d) Mn,04​

Answer 1

• Of the given compounds, Fe₂O₃ does not exhibit different oxidation number of the same element.
• The compound Pb₂O₄ does not exist.
• Fe₃O₄ is a spinel, i.e. in one mole of Fe₃O₄ - 2 Fe atoms exist in +3 oxidation state and one Fe atom exists in +2 oxidation state.
• Fe₂O₃ has Fe in only +3 oxidation state.
• Mn₃O₄ is also a spinel with Mn atoms existing in +2 and +3 oxidation states.

Answer 2

Fe₂O₃ does not exhibit a different oxidation number of the same element.

Option: (c)

Explanation:  

• Oxidation State can be defined as the number of electrons lost, gained or shared in a compound by an element.  

• The compound dilead tetroxide does not exist. Hence it is an incorrect option.

• In $\mathrm{Mn}_{3} \mathrm{O}_{4}$, one of the atom of Manganese has an ‘Oxidation state’ of 2 and two of the atoms of Manganese has an ‘oxidation state’ of three.  

• In $\mathrm{Fe}_{3} \mathrm{O}_{4}$ the oxidation state of two atoms of iron is 3 and Oxidation state of one atom of iron is 2.

• In the correct option is $\mathrm{Fe}_{2} \mathrm{O}_{3}$ since the oxidation state is 3 for all atoms.