In haemoglobin the iron is in oxidation state of

Options

A. ` + 2`
B. ` + 1`
C. ` + 3`
D. `+4`

Explanation

To determine the oxidation state of iron in hemoglobin, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Hemoglobin**: Hemoglobin is a protein found in red blood cells that is responsible for transporting oxygen throughout the body. It contains iron, which plays a crucial role in its ability to bind to oxygen.

2. **Identifying the Iron Ion**: In hemoglobin, the iron is present in a specific oxidation state that allows it to effectively bind with oxygen molecules. The common oxidation states of iron are +2 (Fe²⁺) and +3 (Fe³⁺).

3. **Analyzing the Binding Mechanism**: For hemoglobin to bind oxygen, the iron must be in a state that allows it to form coordinate bonds with oxygen. If the iron were in the +3 oxidation state (Fe³⁺), it would not be able to effectively coordinate with oxygen due to its higher positive charge, which would repel the oxygen molecule.

4. **Conclusion on Oxidation State**: Since the iron in hemoglobin must be able to bind with oxygen, it must be in the +2 oxidation state (Fe²⁺). This allows for the formation of stable coordinate bonds with oxygen, enabling hemoglobin to carry oxygen efficiently.

5. **Final Answer**: Therefore, the oxidation state of iron in hemoglobin is +2.