The brown ring complex compounds is formulated as $\left[Fe{\left(H_{2}O\right)}_5\left(NO\right)\right]S{O}_4$ .The oxidation state of iron is

The brown ring complex, represented as [Fe(H2O)5(NO)]SO4, is a well-known coordination compound. When the brown ring complex dissolves in water, it dissociates into two distinct ions:

• The cation: [Fe(H2O)5(NO)]2+
• The anion: SO42−

To determine the oxidation state of iron (Fe) in the brown ring complex, we analyze the components in the cation [Fe(H2O)5(NO)]2+:

1. The nitric oxide ligand (NO) in the brown ring complex has an oxidation state of +1.
2. Water molecules (H2O) are neutral ligands and do not contribute to the oxidation state.
3. The overall charge of the cation is +2.

Let the oxidation state of iron (Fe) be x. Based on the charges of the ligands and the overall cation charge, the equation becomes:

        x + 5(0) + 1 = +2

Solving for x:

        x + 1 = 2
        x = +1

Therefore, the oxidation state of iron (Fe) in the brown ring complex is +1.

The brown ring complex is a unique coordination compound that exhibits interesting chemical properties, making it a classic example in inorganic chemistry studies.