# What is the metal oxidation state in Fe(SO_4)_2?

That's $F {e}^{4 +}$! It is probably a typo.
The sulfate ion is $S {O}_{4}^{2 -}$. There is a $\text{ferrous sulfate, "FeSO_4", and a ferric sulfate, } F {e}_{2} {\left(S {O}_{4}\right)}_{3}$. $F e \left(I V +\right)$ salts would be rare.