The oxidation number of Fe in Fe2O3 is
The Correct Answer and Explanation is:
Correct Answer:
The oxidation number of Fe in Fe₂O₃ is +3.
Explanation:
To find the oxidation number of iron (Fe) in the compound Fe₂O₃, we need to consider the oxidation rules for compounds. One key rule is that the sum of the oxidation numbers of all atoms in a neutral compound must equal zero.
Fe₂O₃ is a neutral compound made up of two iron (Fe) atoms and three oxygen (O) atoms. Oxygen, in most compounds, has a standard oxidation number of -2. Since there are three oxygen atoms, the total oxidation from oxygen is:
3 × (-2) = -6
Now, let the oxidation number of each iron atom be x. There are two iron atoms, so the total contribution from iron is:
2 × x = 2x
According to the rule mentioned earlier, the sum of all oxidation numbers must equal zero. So we set up the equation:
2x + (-6) = 0
2x – 6 = 0
2x = 6
x = 3
Therefore, the oxidation number of each iron atom in Fe₂O₃ is +3.
This means that in Fe₂O₃, iron has lost three electrons per atom to reach this oxidation state. In chemical terms, Fe is acting as a cation (positively charged ion), and oxygen is acting as an anion (negatively charged ion). Specifically, Fe³⁺ ions combine with O²⁻ ions in a ratio that balances the total charges to zero.
Fe₂O₃ is also known as iron(III) oxide. The Roman numeral III in the name confirms that iron is in the +3 oxidation state in this compound. This is important in redox chemistry and reactions such as smelting, where changes in oxidation number reflect the transfer of electrons.
