00:02
Molecules that have stronger intermolecular forces are harder to pull apart, which is why when two molecules have a strong intermolecular force, they have a higher boiling point, and molecules that have weak intermolecular forces have low boiling points.
00:33
So first let's look at ammonia versus methane.
00:41
So here's ammonia and here's methane.
00:50
The first thing that you should notice is that we have a nitrogen.
00:53
Attached to hydrogen.
00:56
If you remember our rules for hydrogen bonds, we need either a nitrogen, an oxygen, or a fluorine, and we need a hydrogen attached to one of those.
01:12
Now we have that for ammonia, but we don't have that for methane, because a hydrogen attached to a carbon isn't going to be the partially positive and the partially negative that we need, because carbon isn't electronegative enough.
01:29
So because of that, that means that ammonia will be able to nitrogen bond, or hydrogen bond, but methane won't.
01:44
And because hydrogen bonds are stronger bond, are stronger intermolecular forces than vanderwal's interactions, which is the best thing methane can do, that means that ammonia will have the higher boiling point...