00:01
Okay, so for this problem, there are three different parts.
00:04
It's going to be three different strychialmetry problems.
00:07
So for part a, we are starting with 13 .6 grams of nh3, and it's asking us to solve to grams of 02.
00:23
So friendly reminder, grams to grams has to be three steps.
00:28
We have to first convert to moles, then use our molar ratio.
00:30
And finally, we have to convert back to grams.
00:35
So when we do this, the first thing we're going to do, we start with grams of nh3.
00:42
And we already know there's going to be one, two, three steps.
00:54
So the first step, we have to get rid of this gram.
00:56
So grams of nh3, we go on the bottom.
01:00
And the only thing that can go with grams of nh3 is one mole of nh3.
01:04
So one mole of nh3 goes on top to find the molar mass.
01:08
Use the periodic table.
01:10
And if you use the periodic table, you find the mass to be 17 .04.
01:16
To indicate that this is coming from something, let me get a different color.
01:21
So this is 17 .04.
01:25
So this is periodic table.
01:28
So if it's in blue, it's from the periodic table.
01:30
Okay.
01:31
So we've gotten rid of grams.
01:33
We're now at moles.
01:34
So now we're going to use moles in the bottom of this second fraction.
01:38
So this is going to be our molar ratio.
01:40
So we're going to put moles of nh3 on the bottom because that's what we have to get rid of.
01:43
We're trying to get to grams of o2, but we can't go straight to grams yet.
01:47
Instead, we're going to go to moles of o2.
01:51
So when we see mole on top of mole, we have to go up to our balanced chemical reaction.
01:58
So if we look, o2 has a three out front, nh3 has a four out front.
02:06
Therefore, it's going to be a three with o2, and it's going to be a four, with nh3.
02:14
And then last but not least, we need to convert this moles of 02.
02:17
So it's going to be one mole of 02 because we're trying to get grams of 02.
02:23
So this is again where we would use our periodic table.
02:26
And 16 times 2 gives us a mass of 32.
02:30
So then we're going to multiply straight across the top, multiply straight across the bottom, divide those two numbers.
02:36
And when we divide them, we get 19 .2 grams of 02 .2.
02:42
So that is the answer for.
02:44
Part a.
02:47
For part b, it's asking us to determine the amount of n2 produced from 6 .5 grams of not n, i'm so sorry, from 02, so 6 .5 grams of 0 to grams of n2 produced.
03:13
Again, with grams to grams, it's going to be three steps just like it was above.
03:17
So the first step is going to be converting this grams to moles...