It's a state function, so we're at constant temperature and pressure, and now we want to consider some chemical change or a phase transition or you name it.

这就是态函数，我们处于恒定的温度和压强之下，然后考虑某些化学变化或者相变,或者你想考虑的东西。

麻省理工公开课 - 热力学与动力学课程节选

You need a functional form that connects the value at one state of matter, the freezing point of water to another phase change, the boiling point of water.

你需要一个函数形式来,连接物质某个态对应的温度值，如水的冰点，和另一个相变,如水的沸点。

麻省理工公开课 - 热力学与动力学课程节选

Does stuff change phase to go from liquid to solid and so forth, right?

物质是否从液体转变为固体,相变到底在什么位置出现？

麻省理工公开课 - 热力学与动力学课程节选