Salts lower the freezing point of water, as anyone knows who's thrown salt on an icy sidewalk.

盐可以降低水凝固点，在寒冷冬季向多滑地面和过道撒盐就是利用这个原理。

Or in general, why do things have different melting and freezing points?

一般来说，为什么物质会有不同熔点和凝固点？

Well, yeah, but the impurities in the coffee would make it have a depression.

嗯，是，但咖啡中杂质会导致其凝固点降低。

Would it raise the freezing point of gasoline?

这会提高凝固点吗？

Don't worry, Alice! In this case, because of the incredibly high pressure in the core, the freezing point of iron is actually about 6000 degrees!

别担心，爱！于地心处极高压力，铁凝固点高达6000度！

If I had to guess, I think olive oil's freezing point would be pretty low.

如果让我猜话，我觉得橄榄凝固点应该相当低。

But if it's mostly like octane and you put some water in the octane, I think your freezing point would come up.

但如果主要成分是辛烷， 而你又在其中加入了一些水，我想你凝固点会升高。

And that is when we have impure substances, when we have something else mixed in, the freezing point or melting point lowers, which we've talked about before.

这就是当我们有杂质时，即有其他物质混合其中，凝固点或熔点会降低情况，这一点我们之前已经讨论过。

I guess there's a level of which I kind of just thought I do know different things had different melting and freezing points and stuff or whatever.

我想，我大概知道不同物质有不同熔点和凝固点之类，但具体细节我并不太清楚。

The sugar sucrose sets the standard for PAC, which corresponds to how much the freezing point is depressed by, say, one pound of sucrose dissolved in 100 pounds of water.

蔗糖为PAC设定了标准，它对应于溶解在100磅水中一磅蔗糖降低多少凝固点。

So, but with the size of something like a hydrocarbon chain that's short for gasoline, it's like octane is like, I think about the biggest that is not going to have that much of an effect.

所以，对于像这样短碳氢化合物链来说，比如辛烷，我认为这是最大一种， 不会对凝固点产生太大影响。

I like to start the other way from solid and then to liquid and then to gas because for me, that is like very consistently you get a melting point, you don't consistently get a freezing point.

我喜欢从固态开始， 然后到液态， 再到气态顺序来讲解， 因为对我来说，这样更一致——你会明确地得到一个熔点，但你并不总能明确地得到一个凝固点。