The oxidation state of iron in iron(?) ion Fe3+
The Correct Answer and Explanation is:
The oxidation state of iron in the iron(III) ion, Fe³⁺, is +3.
To understand this, let’s break it down:
- Oxidation States and Ions: The oxidation state of an element in an ion is the charge that the ion carries. For a neutral atom, the oxidation state is zero. However, when atoms lose or gain electrons to form ions, they acquire an oxidation state that corresponds to the number of electrons lost or gained.
- Fe³⁺ Ion: The iron ion in question is Fe³⁺, which indicates it has a +3 charge. This means that the iron atom has lost three electrons.
- Electron Configuration: The electron configuration of a neutral iron atom (Fe) is: [Ar]3d64s2[Ar] 3d^6 4s^2[Ar]3d64s2 In the case of Fe³⁺, three electrons are lost. These are typically removed first from the 4s orbital, followed by the 3d orbitals. This results in the electron configuration: [Ar]3d5[Ar] 3d^5[Ar]3d5 This shows that the iron atom has now lost three electrons and has a net positive charge of +3.
- Why +3?: The iron atom starts with an atomic number of 26, meaning it has 26 electrons in its neutral state. By losing three electrons to form Fe³⁺, the number of electrons is reduced to 23, which is why it carries a +3 charge.
- General Rules: Iron can form ions with different oxidation states, commonly +2 and +3. The +3 state (Fe³⁺) is more stable in certain compounds, such as iron(III) chloride (FeCl₃), where iron is in the +3 oxidation state.
In conclusion, the oxidation state of iron in the Fe³⁺ ion is +3, reflecting the loss of three electrons from the neutral atom.
