Question

[Fe(CN)₆]⁴⁻ is a coordination complex ion.

Calculate the oxidation number of iron in the complex.

Answer 1

x + 6(−1) = −4 

x − 6 = −4 

x = −4 + 6

∴ x = +2

∴ The oxidation number of iron in [Fe(CN)₆]⁴⁻ is +2.