00:02
There, in this question, we are working with potassium permanganate, which has the formula kmno4.
00:12
All right, and we want to know the charge or the oxidation number of the manganese in this formula.
00:18
So we need to remember some of the rules for assigning oxidation numbers.
00:22
First of all, a compound is neutral.
00:31
So what that means is that the oxidation numbers must add up to zero.
00:39
All right, the next thing that we're going to remember about oxidation numbers is that oxygen has an oxidation number of negative 2, unless it's in a peroxide, but this is not a peroxide.
01:04
So our oxygen here is going to be negative 2.
01:10
All right, for the potassium, we remember that the oxidation number of an ion is equal to its charge.
01:22
So potassium is a group 1 metal and group 1a metals all form ions with a single positive charge.
01:38
So therefore its oxidation number is positive 1.
01:42
Ok, so we have all the information we need here.
01:44
We just need to do a little calculating because we're going to go back to our first rule here...
