00:01
All right, so today we have mass for calculation composition for really just sulfur containing compounds.
00:08
We're just going to focus on the sulfur.
00:12
So we have like five examples here.
00:15
I'm going to work through the first two and speed up a little bit towards the for the last three.
00:21
Our first compound is sodium sulfy and a 2 -s -o -4.
00:24
The first thing that need to do is to determine the molar mass of the entire compound.
00:30
So i'm just kind of show you that's going to be two times the mass of sodium, which is 23 .0.
00:38
And we're going to add to that our sulfur.
00:41
There is one sulfur, the 32 .1.
00:45
And then we are going to add our oxygen.
00:50
There is four oxygen.
00:51
So that's going to be four times 16 .0.
00:55
And from that, we're going to get a total mass of 142 .1.
01:04
So now to determine the percentage of that sulfur, so we're going to take a ratio of our mass of sulfur to our mass of the compound.
01:14
Now, i'm not putting units here, just save space, but these are grams per bowl, kind of using the molar mass of the elements for this.
01:23
So we have 32 .1 over our 142 .1 times 100.
01:31
And this is going to give us 22 .6 % sulfur, and that is for our sodium sulfate.
01:42
So the remaining ones, again, we're going to do aluminum.
01:46
So we have two aluminums.
01:47
That's going to be two times 27 .0.
01:51
And to that, we're going to add the three sulfur.
01:55
So that's three times 32 .1...