What is the oxidation number of Mn in the compound:
KMnO4
I came up with 7, but the answer key says I am wrong
2007-09-30 14:36:37 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
The answer key is incorrect. The oxidation number on Mn in this case is 7
Oxygen in compounds is always -2 expect for then it's a peroxide, which this is not.
Permanganate, MnO4, has a charge of -1
The oxidation numbers in a polyatomic must add up to the charge on the polyatomic.
Mn + 4 * Oxygen = -1
Mn + 4 * -2 = -1
Mn - 8 = -1
Mn = 7
2007-09-30 14:40:52 · answer #1 · answered by lhvinny 7 · 0⤊ 0⤋
I also came up with 7+... sorry
O... has 2- (and there are 4 of them)
Now K (which has 1+)
So 8- + 1+ = 7- so you need 7+
2007-09-30 14:43:21 · answer #2 · answered by ? 3 · 0⤊ 0⤋
it IS +7
the K is +1
each O is -2
the Mn MUST be +7
2007-09-30 14:42:00 · answer #3 · answered by chem geek 4 · 0⤊ 0⤋