00:01
All right, so we have the following three scenarios, and we want to know whether the entropy is positive or negative.
00:06
So entropy being positive just means that the amount of disorder in the system has increased and vice versa for negative.
00:12
So if we start with water vapor and it condenses, what's happening is the water vapor gas is turning into a liquid.
00:19
And when you go from a gas to a liquid, you become more ordered because the liquid particles won't vibrate as much.
00:25
There's more intramelcular forces holding them together.
00:27
So that means that the entropy change is going to be negative.
00:31
Entropy will go down.
00:33
All right.
00:33
What about when water boils? so in this case, you're doing the opposite of in part a.
00:38
The liquid is turning into a gas and it's becoming increasingly disordered as molecules can move faster.
00:43
They're less bound together...