+7 to +2
+6 to +2
+5 to +2
+4 to +2
Correct answer is A
\(MnO_{{4}{(aq)}}\) has a charge of \(-1\)
Let the oxidation number of \(Mn\) in \(MnO_{{4}{(aq)}}\) be X
Recall, the oxidation number of \(O_{2}\) is \(-2\)
\(\therefore\) \(X + (-2\times 4) = -1\)
\(X - 8 = -1\)
\(X = +7\)