The brown ring complex compound is formulated as `[Fe(H_(2)O)_(5)NO]SO_(4)`. The oxidation state of `Fe` is

Explanation

Sum of oxidation of all atoms in neutral compound is zero. Let the oxidation state of iron in the complex ion
`[Fe(H_(3)O)_(5)(NO)]^(2+)SO_(4)^(2-) "be then" x+5 xx 0 + 1 = +2 implies x = +1`