MnO4(aq) + 8H + 5Fe2+ (to) Mn2+(aq) + 5Fe3+(aq) + H2O. The oxidation number of maganese in the above reaction changed from
-
A.
+7 to +2 -
B.
+6 to +2 -
C.
+5 to +2 -
D.
+4 to +2
Correct Answer: Option A
Explanation
(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 + (-2times 4) = -1)
(X – 8 = -1)
(X = +7)