00:01
In this video, we want to take the given half reactions and turn them into balanced spontaneous reactions.
00:07
For the first one, we see that the reduction potential for 03 to 02 is greater.
00:13
So this is going to be reduced.
00:16
And the other one will be oxidized, so we're going to write it backwards.
00:21
So that means we have 03 to 02 as one reaction, and then n0 to n03.
00:33
Minus as the other reaction.
00:37
All right.
00:40
So for 03 and 02, we have both of the oxidation numbers are zero here because they're molecular in nature.
01:00
But the atoms are not balanced and it's because of oxygen.
01:06
So that means we can add, let's see, if we add a water here, this will give us the right number of oxygens, and then we'll need a 2h plus.
01:20
And then the charge is off, so we'll need two electrons.
01:27
That way we have three oxygens, two hydrogens, and all the charges are balanced.
01:32
For this reaction right here, all atoms other than hydrogen and oxygen are balanced.
01:38
Let's look at the oxidation number.
01:40
So this is a minus 2.
01:41
That means it's a plus 2.
01:42
And this is going to be a minus 6 overall, 3 times 2.
01:45
So this needs to be a plus 5.
01:48
So that means that we need to lose three electrons to go from the five to the two.
01:54
Lose because it's an oxidation process.
01:56
Then we have a negative 4 versus a 0, so we'll add 4h pluses.
02:02
And that means we need to add 2h2 here, and that also balances out the oxygen.
02:07
All right, so this is three electrons, so this needs to be multiplied by 2.
02:14
And then this is 2 electrons, so it needs to be multiplied by 3.
02:16
And then that with a number of electrons will cancel out.
02:19
So our overall is going to be 303, and then we have two times three, six h pluses, but we have eight over here.
02:30
So this means we're going to have two h pluses net, eight minus six, and then we'll get rid of this.
02:36
Electrons cancel out, and then we have two no.
02:42
We have four h2os here and three here, so that's a net of one h2o, and this is going to cancel out.
02:51
And then on the other side we have 3 .02 plus 2 and 03 minus and we already did the h plus.
03:01
Let's just make sure that that's balanced in mass and charge.
03:05
So the minus 2 and the plus 2 versus a 0, so all the charge is good.
03:10
Then we have, let's see, two nitrogen, two hydrogens, and 9, 10, 11, 12.
03:19
This is 6 plus 6 is 12, oxygens...