And we saw that in fact in this case delta S of mixing, we calculated it, saw that it is positive.
实际上如果我们计算气体混合过程中,熵的变化,我们会发现这个量是正的。
But at the same time, entropy is going to be favoring whichever side has higher entropy, has more disorder, and there's a balance that's achieved.
但是同时熵的变化可能,支持反应向着具有更高熵更无序的方向进行,这就是最终达到的平衡。
As soon as you allow anything to mix, like you might if you want to do any chemistry, entropy changes.
只要你允许物质混合,就像你做任何化学实验的时候要做的,熵就会发生变化。
Even though the signs of the enthalpy changed, and the signs of the entropy changed because it's a combination of the two that matters.
即使自由焓的符号发生变化,熵的符号也会发生变化,因为这两部分都起作用。
Well, I can, for any given case, measure the pressure, determine the entropy and I'll know what the slope of change will be.
好的,对特定的情况,我可以测量压强,确定熵,并且知道这就是变化的速率。
What happens to the thermodynamics parameters, and see the results in terms of the parameters including entropy.
以及用这些热力学参量,表示的物理量是怎么变化的,看结果是什么,这其中就包括了熵。
So, I just want to write a few examples down with a few values for delta u or delta H or delta S, and see whether we can get any clues from what we see.
我先写一些例子,例子包含一些内能,自由焓和熵的变化数值,然后看从中,我们能不能得到一些启示。
Then the second derivative gives the change in entropy with respect to the variable that we're differentiating, with respect to which is either pressure or volume.
二阶导数给出熵,随着变量变化的情况,这些变量包括压强或者体积。
Do we calculate, you know, delta S, delta u, delta H?
是否要计算熵的变化,内能的变化,自由焓的变化?
So that tells us what to do to know the entropy as the temperature changes.
这告诉我们当温度变化时,如何得到熵的数值。
Namely, it's delta S is greater than zero.
变化过程中熵的变化总是大于零的。
Change in entropy is greater than zero for an isolated system.
对孤立系统,熵的变化是大于零的。
In other words, the order of taking the derivatives with respect to pressure and temperature doesn't matter And what this will show is that dS/dp dS/dp at constant temperature, here we saw how entropy varies with volume, this is going to show us how it varies with pressure.
换句话说,对温度和压强的求导顺序无关紧要,结果会表明,恒定温度下的,对应我们上面看到的,熵如何随着体积变化,这个式子告诉我们,熵如何随着压强变化。
And the useful outcome of all that is that p we get to see how entropy changes with one of those variables in terms of only V, T, and p, which come out of some equation of state.
这样做的重要结果是,我们得到了熵随着V,T或者,其中一个变量变化的情况,这些可以从状态方程得到。
H We also saw that dS for constant H and p was greater than zero.
我们同样可以看到如果保持自由焓,和压强不变熵的变化dS也是大于零的。
T That dS is greater than dq over T.
对吗,熵的变化dS大于热量dq除以温度。
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