Question

what is the oxidation number of Mn in KMnO4

Answer 1

oxidation no.
...(+1)+x+(-2)4=0
1+x -8 =0
....x=7
so oxidation no i s 7

Answer 2

KMnO4
| |
+1 -8
-8+1=-7
so Mn is 7
so that -7 and 7 will be cancelled out and we get KMnO4