So if we're going to be writing our equilibrium constant in terms of mole fractions, we're going to need mole fractions.

所以如果我们把平衡常数写作，摩尔分数的函数，我们需要知道摩尔分数。

youdao

Writing at equilibrium that the change in the concentration of one of the species is equal to zero, we're going to use that as an approximation also later, when we get to more complicated mechanisms.

这写着在平衡状态一种物质，的浓度变化等于零，我们一会儿也会把它用作一种近似，当我们学习更复杂的机理的时候。

youdao

SO there's nothing that forbids us from just writing minus a equilibrium here.

所以没有什么妨碍我们在这写，减去A平衡。

youdao

So let's start by writing down our definition of equilibrium.

一开始,我们先写出平衡的定义。

麻省理工公开课 - 热力学与动力学课程节选