00:01
Okay, so we're going to find the empirical formula of menthol.
00:03
So i'm going to write out a very general skeleton equation for this reaction, just so i can see all the elements.
00:11
So i don't know how many, how much carbon, hydrogen, oxygen is in menthol.
00:17
So i'm going to write a cx, h, y, o, z, plus oxygen is going to give us water and carbon dioxide.
00:31
And since i can't balance this equation, i'll just say this is a, b, c, and d.
00:38
Because you don't really need to balance it for what we're going to do here.
00:42
So we are told we have a total of 5 .025 times 10 to the minus 2 milligrams of menthol.
00:53
We are told we produced 5 .795 times 10 to the minus 2 milligrams of water.
01:01
And 0 .1415 milligrams of carbon dioxide.
01:07
So what i'm going to look at is i need to figure out the amount of carbon, hydrogen, and oxygen in menthol, but i need to use the rest of the equation to do that.
01:16
The fact that the only place this carbon after it burnt went to went 100 % into the carbon dioxide, i'm going to focus on finding out how much carbon is in this carbon dioxide, because that will be the amount of carbon in the menthol.
01:35
So finding carbon.
01:41
I'm first going to convert my, oops, hold on.
01:46
I had to convert the milligrams to grams.
01:49
So i'm going to first convert my carbon dioxide, which is 1 .415 times 10 to the minus 4 grams of carbon dioxide, since there's a thousand milligrams in a gram.
02:04
And in one mole of carbon dioxide, there's 44 .01 grams.
02:13
So that's going to give me 3 .215 times 10 to the minus 6 moles of carbon dioxide.
02:21
I'm now going to look at 3 .215 times 10 to the minus 6 moles of carbon dioxide.
02:32
And i know looking at the balanced equation, every one mole of carbon, there's one mole of carbon dioxide, which is going to give me 3 .215 times 10 to the minus 6 moles of carbon.
02:49
And then i can convert that moles of carbon to grams of carbon, knowing that there's 12 .01 grams and one mole of carbon.
03:04
Which will give me 3 .861 times 10 to the minus 5 grams of carbon.
03:13
So i now know two important things.
03:16
I know the moles of carbon and i know the mass of carbon in menthol.
03:23
Because they'd be equal, because all the carbon in carbon dioxide is the carbon in the menthol.
03:30
So next i'm going to find, i'm going to use hydrogen.
03:34
The reason why i'm focusing on hydrogen is because 100 % of this hydrogen went to the water.
03:42
So i can use the water.
03:44
I can't use oxygen because this oxygen and there's oxygen here and here and here.
03:49
There's multiple sources of oxygen and there's multiple locations.
03:53
So i need to focus on one that's in one place only.
03:57
So i'm going to convert my water, which is going to be 5 .795 times 10 to.
04:08
To the minus 5 grams of water because again i had to convert it from milligrams to grams knowing that in one mole of water we have 18 .02 grams of water which is going to give me 3 .216 times 10 to the minus 6 moles of water.
04:33
I'm then going to convert that 3 .216 times 10 to the minus 6 moles of water.
04:34
I'm then going to convert that 3 .216 times 10 to the minus 6 moles of water.
04:40
Into moles of hydrogen, knowing that looking at the formula, for every two hydrogen, there's one water...