Question

In the permanganate ion MnO4-, the oxidation number of each oxygen atom is -2. What is the oxidation number of the manganese ion?

A. +1
B. +2
C. +7
D. +8

Answer 1

To determine this simply multiply the number of oxygen atoms by the oxidation number for each oxygen atom, which is 4 • -2 = -8. Then knowing we have 1 Mn atom, it would be 1 • x, where x is the unknown oxidation state for Mn.

X + - 8 = overall charge of compound

X + - 8 = -1

X - 8 = -1

X = 7.

The solution is C.