Let's try it with a different equation of state, that isn't quite as simple as the ideal gas case.
考虑一个不同的状态方程,这状态方程不像理想气体状态方程那么简单。
So let's take our one model that we keep going back to Equation of state, and just see how it works.
我们回到经常使用的理想气体模型,或者说状态方程。
I know I only need 2, so I can relate dV dV to dp through the ideal gas law.
我只需要两个就够了,因此可以用,理想气体状态方程消去。
For real gases, there's a whole bunch of equation the states that you can find in textbooks, and I'm just going to go through a few of them.
这是理想气体的状态方程,对实际气体,你可以在教科书里,找到许多描述它们的,状态方程。
Or, if we know the equation of state from a model, ideal gas, van der Waal's gas, whatever, u now we can determine u.
或者如果我们知道模型的状态方程,比如理想气体,范德瓦尔斯气体,无论什么,我们就可以利用状态方程得到内能。
So from measured equation of state data, or from a model like the ideal gas or the van der Waal's gas or another equation of state you know this.
所以,从测量的到的状态方程的数据,或者从状态方程模型比如理想气体方程,范德瓦尔斯方程或者其他状态方程,我们就可以知道。
So again, if you do a calculation where you're close enough to the ideal gas and you need to design your, if you have an engineer designing something that's got a bunch of gases around, this is a useful thing to use.
要研究近似理想气体的表现时,这个方程非常有用,下面再来看一个,对我们来说最有意思的,实际气体状态方程:,范德瓦尔斯方程。
pV=RT p plus a over v bar squared times v bar minus b equals r t. All right if you take a equal to zero, these are the two parameters, a and b. If you take those two equal to zero you have p v is equal to r t.
我们就回到,也就是理想气体,状态方程,下面我们来看看,这个方程。
nRT So, dp/dT, for our ideal gas, at constant volume, remember pV is nRT.
对于理想气体状态方程pV等于,所以对理想气体。
So what happens then we're going to use the ideal gas law. So it's approximately delta u plus delta nRT. That's a constant. That's a constant.
我们现在要应用理想气体物态方程,这个近似等于ΔU加上Δ,这是常数,这是常数。
应用推荐