00:03
So one of the things we often look at in chemistry is trying to calculate the theoretical yield or how much of a substance i should make.
00:11
And you can think of the theoretical yield based on theory.
00:14
It's what i should predict that i should form from my balanced stoichiometric equation if all of the limiting react, say, is completely used up.
00:24
This is how much i should potentially make.
00:26
And so one way to look at this, if we take a look, say, of water, simple equation.
00:33
So h2 plus o2 to produce water, h2.
00:42
But we can see that in order to balance this chemical equation, that i'm going to have to have a two in front of there to balance my oxygens, and thus i'm going to have to have a two here.
00:53
So for every two moles of hydrogen, it requires one mole of oxygen, and i'll produce, say, two moles of water.
00:59
And so if my limiting reactant in this case, if i only have two moles of hydrogen, if that's all used up, i should produce two moles of water.
01:07
We could say, well, what if i wanted to multiply this times two, and i ended up maybe what if i have, say, four moles of hydrogen and two moles of oxygen, i should produce four moles of water.
01:27
And let's say i have excess oxygen.
01:29
I've got plenty of oxygen available, but i'm only limited to four moles of hydrogen...