The oxidation state of Iron in $Fe(CO)_{5}$ is

Question

Accepted Answer

The oxidation state of Iron in $Fe(CO)_{5}$ is determined by considering the charge of the ligand and the overall charge of the complex.

**Explanation for Option 1 (0) being correct:**

1.  **Nature of the Ligand:** Carbon monoxide (CO) is a neutral ligand. This means that when it coordinates to a metal, it does not carry any charge. Its oxidation state is 0.
2.  **Overall Charge of the Complex:** The complex $Fe(CO)_{5}$ is a neutral molecule. There is no positive or negative charge indicated for the complex.
3.  **Calculation of Oxidation State:** To find the oxidation state of Iron (Fe), we can set up an equation:
    (Oxidation state of Fe) + (Number of CO ligands × Oxidation state of CO) = (Overall charge of the complex)
    Let 'x' be the oxidation state of Fe.
    x + (5 × 0) = 0
    x + 0 = 0
    x = 0
    Therefore, the oxidation state of Iron in $Fe(CO)_{5}$ is 0. This is a common characteristic of many neutral metal carbonyl complexes, where the metal is in a zero oxidation state.

**Explanation for other options being incorrect:**

*   **Option 2 (2) is incorrect:** If the oxidation state of Iron were +2, then the overall charge of the complex $Fe(CO)_{5}$ would be +2 (since CO is neutral). However, $Fe(CO)_{5}$ is a neutral molecule, not an ion with a +2 charge.
*   **Option 3 (3) is incorrect:** If the oxidation state of Iron were +3, then the overall charge of the complex $Fe(CO)_{5}$ would be +3. This contradicts the fact that $Fe(CO)_{5}$ is a neutral compound.
*   **Option 4 (5) is incorrect:** If the oxidation state of Iron were +5, then the overall charge of the complex $Fe(CO)_{5}$ would be +5. This is not consistent with the neutral nature of the $Fe(CO)_{5}$ molecule. Furthermore, an oxidation state of +5 is extremely rare for iron, especially in a neutral carbonyl complex.