00:01
Okay, so i'm going to write this out kind of in generic terms.
00:06
We've got a vanadium oxide, and we're going to react it with hydrogen.
00:13
And some of that oxygen is going to come off and make water, and we're going to be left with a new oxide.
00:22
So i left the x there because none of the vanadium is leaving, but the number for z will be less than y.
00:29
And then we'll take that oxide, vx, o, z, and react it with some more hydrogen.
00:39
Again, to make some more water.
00:42
And now we're just left with vanadium.
00:45
Okay.
00:45
So the amount of vanadium that we're left with, which is 2 .573 grams, that's got to be the same amount of vanadium that was in these compounds.
00:58
Okay? whatever we started with is what we ended up with.
01:01
So when we go to do some simple formulas, we'll know how many grams of vanadium we have.
01:08
For this first one, they told us we started with 4 .589 grams.
01:16
And the second one here we had 3 .782 grams.
01:22
So if i know the mass of vanadium in there, i should be able to subtract and find the mass of the oxygen in there.
01:29
So let's go ahead and start with our vxoz.
01:35
Okay.
01:37
So i know in here i have 2 .573 grams of vanadium.
01:44
Okay.
01:45
And i know that i have 3 .782 minus 2 .573.
01:55
So that's going to give me 1 .209 grams.
02:00
And that's our mass of oxygen, okay? because the whole thing has to be, has to add up to the total, and it's just vanadium and oxygen.
02:07
So now we're just going to go ahead and change our grams to moles and get our simplest ratio.
02:17
So vanadium is 50 .94, and oxygen is 16.
02:27
Okay, so we're going to get 0 .05, 0 .05 moles of vanadium here.
02:34
And we're going to get 0 .07, 6 moles of o.
02:42
So now to get a simple whole number ratio, we'll divide them both by the smallest number.
02:49
So we'll get one.
02:55
And for this one, we're going to get 1 .5.
03:00
So i'm going to have to go ahead and multiply this by two, and this by two, so we can get some whole numbers.
03:07
So we can see this is going to be 2 to 3.
03:11
So this compound right here was v2 -03.
03:16
So we found one of our simplest formulas.
03:19
Now let's do the other one...