Question

What is the oxidation state of iron in the complex, [FeCl4]2–? Show how you arrived at your answer.

Answer 1

Ia an ion the sum of oxidation states of the elements should be equal to the charge of an ion.

Let oxidation state of Fe be x, then

$$[Fe^xCl_4^{-1}]^{2-}$$

$$x\times1 + (-1)\times 4 = -2$$

$$x= +2$$

Oxidation state of Fe is +2.