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00:00:00,600 --> 00:00:05,160
We're told that glucose reacts
with oxygen to give carbon

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00:00:05,160 --> 00:00:07,240
dioxide and water.

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00:00:07,240 --> 00:00:11,190
What mass of oxygen, in grams,
is required to complete the

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00:00:11,190 --> 00:00:15,950
reaction of 25 grams
of glucose?

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00:00:15,950 --> 00:00:18,990
And they also want to know what
masses of carbon dioxide

6
00:00:18,990 --> 00:00:20,405
and water are formed?

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00:00:20,405 --> 00:00:23,160
Well let's first just
write the reaction.

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00:00:23,160 --> 00:00:27,540
So they're saying glucose reacts
with oxygen to give

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00:00:27,540 --> 00:00:30,030
carbon dioxide and water.

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00:00:30,030 --> 00:00:41,560
So glucose, C6H12O6, reacts with
oxygen in its molecular

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00:00:41,560 --> 00:00:43,595
form-- there's two
atoms there.

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00:00:43,595 --> 00:00:46,630


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00:00:46,630 --> 00:00:51,135
The products are carbon
dioxide and water.

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00:00:51,135 --> 00:00:54,200


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00:00:54,200 --> 00:00:56,450
And you might already
recognize this.

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This is a stoichiometry
problem.

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00:00:58,250 --> 00:01:01,260
They're saying, hey, we have
25 grams of glucose.

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How much oxygen is required
to completely

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00:01:03,370 --> 00:01:04,780
react with that glucose?

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00:01:04,780 --> 00:01:07,630
And then how much carbon dioxide
and how much water is

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going to be produced in grams?

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00:01:09,850 --> 00:01:12,720
That's what stoichiometry
problems are all about.

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00:01:12,720 --> 00:01:16,250
And if you remember from the
last video, the first thing

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00:01:16,250 --> 00:01:18,210
you should always do
is make sure that

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00:01:18,210 --> 00:01:19,550
your equation is balanced.

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So let's make sure
it's balanced.

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On the left hand side-- and you
always want to do the most

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complicated molecules first,
and then do the simplest

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molecules last, because those
are the easiest ones to

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balance out.

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So on the left hand side, here,
I have a 6 carbons.

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On the entire left hand side.

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00:01:38,490 --> 00:01:41,050
On the right hand side,
I only have 1 carbon.

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So let me multiply this
over here by 6.

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00:01:45,110 --> 00:01:49,380
And now I have 6 carbons on both
sides of this equation.

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00:01:49,380 --> 00:01:50,490
Let's move to the hydrogens.

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I have 12 hydrogens
on the left hand

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side of this equation.

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The 12 are all sitting right
there in the glucose.

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00:01:56,740 --> 00:01:58,850
How many do I have on
the right hand side?

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00:01:58,850 --> 00:02:00,910
Well I only have 2 hydrogens.

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00:02:00,910 --> 00:02:04,120
So let me multiply
that times 6.

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00:02:04,120 --> 00:02:06,210
And I didn't mess with the
carbons at all, so that

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00:02:06,210 --> 00:02:09,650
shouldn't change anything-- so
now I have 12 hydrogens on

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00:02:09,650 --> 00:02:10,759
both sides of this equation.

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12 here, 12 there.

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00:02:12,850 --> 00:02:14,690
And now I can just balance
out the oxygen.

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00:02:14,690 --> 00:02:17,030
I saved that for last because
I just have the oxygen

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00:02:17,030 --> 00:02:17,650
molecule here.

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00:02:17,650 --> 00:02:19,450
That's the easiest
one to balance.

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00:02:19,450 --> 00:02:21,470
So how may oxygens do I have
on the right hand side?

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00:02:21,470 --> 00:02:23,380
I have 6 times 2 here.

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00:02:23,380 --> 00:02:25,760
I have 12 oxygens there.

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00:02:25,760 --> 00:02:28,660
And then I have another
6 oxygens over here.

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So plus 6 oxygens.

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00:02:30,600 --> 00:02:35,310
I have 18 oxygens on the right
hand side of my equation.

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00:02:35,310 --> 00:02:37,400
So I need to have 18
oxygens on the left

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00:02:37,400 --> 00:02:38,870
hand side of my equation.

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00:02:38,870 --> 00:02:40,660
How many do I have right now?

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00:02:40,660 --> 00:02:45,500
I have 6 oxygens over here.

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So I'm going to need
12 over here.

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Right?

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This is the last thing
I want to mess with.

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I don't want to put a
coefficient out here.

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That'll change everything
else.

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00:02:53,320 --> 00:02:54,630
I just want to put a
coefficient here.

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00:02:54,630 --> 00:02:56,610
That'll make everything
balance out.

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00:02:56,610 --> 00:02:58,450
I have 18 on the right
hand side.

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00:02:58,450 --> 00:03:00,440
I already have 6 here.

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I want to have 12 right here.

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00:03:02,580 --> 00:03:05,150
So let me multiply
this times 6.

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00:03:05,150 --> 00:03:06,470
And now everything
should work out.

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00:03:06,470 --> 00:03:08,580
I have 6 carbons
on both sides.

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00:03:08,580 --> 00:03:11,640
I have 12 hydrogens
on both sides.

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00:03:11,640 --> 00:03:13,980
And I have 18 oxygens.

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Six here, 12 here.

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00:03:16,100 --> 00:03:17,170
12 here, 6 here.

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00:03:17,170 --> 00:03:20,870
I have 18 oxygens on both
sides of this equation.

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00:03:20,870 --> 00:03:23,260
Now, the next thing we're going
to want to do is figure

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00:03:23,260 --> 00:03:26,290
out how many moles of the
reactants that they're telling

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00:03:26,290 --> 00:03:29,150
us about that we have. So
they're telling us that we

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00:03:29,150 --> 00:03:37,040
have 25.0 grams of glucose.

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00:03:37,040 --> 00:03:40,780
So let's figure out how many
moles per gram, or how many

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00:03:40,780 --> 00:03:43,690
grams per mole, there are
of a glucose molecule.

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00:03:43,690 --> 00:03:45,440
And since everything here is
dealing with carbons, and

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oxygens, and hydrogens, let's
look up the atomic weights of

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all of them.

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So carbons, hydrogens, and
oxygens are pretty common.

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00:03:53,750 --> 00:03:55,280
So at some point you might
want to memorize

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00:03:55,280 --> 00:03:56,050
their atomic weights.

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00:03:56,050 --> 00:04:00,230
And I want to give proper credit
to the person whose

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periodic table I'm using.

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Le Van Han Cedric.

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I got this off of Wikimedia.

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It's a creative commons
attribution license.

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So I want to make sure I
attribute the person who made

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the periodic table.

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00:04:11,330 --> 00:04:12,690
But we have oxygen.

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It has an atomic weight
of 15.9999.

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00:04:17,970 --> 00:04:20,769
Usually it's given as 16.

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00:04:20,769 --> 00:04:21,990
But I'll just write
it like that.

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So oxygen is 15.999.

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And we're going to
have to figure

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out carbon, and hydrogen.

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00:04:32,810 --> 00:04:36,190


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Let's go back to the
periodic table.

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We have carbon, has an atomic
weight of 12.011.

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And hydrogen is 1.0079.

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So let's do the carbon,
12.011.

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So the carbon is 12.011.

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00:04:59,350 --> 00:05:02,900
And then the hydrogen-- remember
atomic weights are

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all the weighted average
of all of the isotopes

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on earth-- is 1.0079.

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1.00-- what was it?

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Was it one zero or two zeroes?

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It was two zeroes.

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00:05:17,060 --> 00:05:20,560
1.0079.

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So what's the atomic weight of
glucose, given all of that?

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00:05:26,110 --> 00:05:28,230
So what's the atomic
weight of glucose?

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00:05:28,230 --> 00:05:30,500
Let me scroll down
a little bit.

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00:05:30,500 --> 00:05:37,710
So the atomic weight of glucose,
C6H12O6, it's going

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to be equal to 12.011 times 6.

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00:05:42,580 --> 00:05:46,110
6 times 12.011.

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00:05:46,110 --> 00:05:48,900
Plus 12 times hydrogen.

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00:05:48,900 --> 00:05:50,900
Just to keep things simple,
actually, let me just make

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this into 16.

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00:05:53,360 --> 00:05:56,630
let me make this into 12, and
let me make this into 1.

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That's going to make our
math a lot easier.

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00:05:59,110 --> 00:06:01,710
So let me just do
it like that.

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Let me clear this.

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So the atomic weight of glucose
is 6 times the atomic

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00:06:10,570 --> 00:06:11,770
weight of carbon.

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00:06:11,770 --> 00:06:13,960
Six times 12.

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00:06:13,960 --> 00:06:15,450
Six times 12.

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00:06:15,450 --> 00:06:17,720
Plus 12 times the atomic
weight of hydrogen.

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00:06:17,720 --> 00:06:22,380
Plus one times 12, or maybe I
have to write 12 times one,

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just to be consistent.

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12 times one.

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Plus 6 times the atomic
weight of oxygen.

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00:06:29,320 --> 00:06:31,320
Plus 6 times 16.

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00:06:31,320 --> 00:06:31,930
So what is this?

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00:06:31,930 --> 00:06:35,830
This is equal to 72 plus 12.

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00:06:35,830 --> 00:06:41,870
Plus, 6 times 16
is 60 plus 36.

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It's 96.

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00:06:45,490 --> 00:06:50,020
And that is-- I'll get the
calculator out-- 72.

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Plus 12, plus 96,
is equal to 180.

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00:06:58,530 --> 00:07:03,870
So the atomic weight of glucose
is equal to 180.

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00:07:03,870 --> 00:07:08,940
Which tells us, that let me
start doing the problem.

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00:07:08,940 --> 00:07:13,790
We have 25.0 grams of glucose.

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00:07:13,790 --> 00:07:19,780
So I'll just write
grams of C6H12O6.

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00:07:19,780 --> 00:07:23,490
We want to write this in terms
of moles of glucose.

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00:07:23,490 --> 00:07:28,410
So we want to cancel out the
grams. So we want the grams in

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00:07:28,410 --> 00:07:29,640
the denominator.

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00:07:29,640 --> 00:07:29,890
Right?

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00:07:29,890 --> 00:07:30,730
Here it's in the numerator.

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00:07:30,730 --> 00:07:34,750
If we divide by that unit, we're
going to cancel it out.

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00:07:34,750 --> 00:07:42,390
So we want the grams of C6H12O6,
or the grams of

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00:07:42,390 --> 00:07:43,730
glucose in the denomenator.

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00:07:43,730 --> 00:07:50,180
And we want the moles of glucose
in the numerator.

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00:07:50,180 --> 00:07:54,520
Because then when we perform
this calculation, that will

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00:07:54,520 --> 00:07:57,270
cancel with that, and we will
be left with moles.

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00:07:57,270 --> 00:07:59,070
So how many grams per mole?

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00:07:59,070 --> 00:08:00,290
Well why don't we just
figure it out?

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00:08:00,290 --> 00:08:02,800
The atomic weight is a 180.

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00:08:02,800 --> 00:08:03,970
So it's 180.

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00:08:03,970 --> 00:08:08,870
If we have Avagadro's number of
these molecules, it's going

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00:08:08,870 --> 00:08:15,140
to have a mass, I should say,
of 180 grams per mole.

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00:08:15,140 --> 00:08:19,150
That's the information we got
by figuring out glucose's

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00:08:19,150 --> 00:08:19,900
atomic weight.

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00:08:19,900 --> 00:08:22,010
So let's just perform
this calculation.

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00:08:22,010 --> 00:08:26,220
These units cancel out
with those units.

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00:08:26,220 --> 00:08:29,940
And so we just take 25 times
one, divided by 180.

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00:08:29,940 --> 00:08:34,018
So this is equal
to 25 over 180.

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00:08:34,018 --> 00:08:35,950
And all were left
with in units is

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00:08:35,950 --> 00:08:42,806
moles C6H12O6, or glucose.

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00:08:42,806 --> 00:08:46,330
And what is 25 five
divided by 180?

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00:08:46,330 --> 00:08:49,820
I should say 25.0 just so we
know that we have three

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00:08:49,820 --> 00:08:52,840
significant digits here.

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00:08:52,840 --> 00:08:54,960
And I don't want to
be too particular

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00:08:54,960 --> 00:08:55,870
about significant digits.

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00:08:55,870 --> 00:08:58,080
Sometimes I'm a little bit
loosey goosey about it.

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00:08:58,080 --> 00:09:00,370
And I was already loosey goosey
about the topic weight.

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00:09:00,370 --> 00:09:02,160
But we'll try to be someplace
in the ballpark.

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00:09:02,160 --> 00:09:12,420
So 25 divided by 180
is equal to 0.139.

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00:09:12,420 --> 00:09:20,060
So we have 0.139 moles of-- I'm
tired of writing, I'm just

186
00:09:20,060 --> 00:09:23,100
going to write-- moles
of glucose.

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00:09:23,100 --> 00:09:28,180
Now, we want to figure out how
many moles of oxygen-- or,

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00:09:28,180 --> 00:09:31,160
well, the first step we want
to figure out is for every

189
00:09:31,160 --> 00:09:34,150
mole of glucose, how many
moles on oxygen?

190
00:09:34,150 --> 00:09:34,860
And we know that.

191
00:09:34,860 --> 00:09:36,400
It's 1 to 6.

192
00:09:36,400 --> 00:09:37,660
So let's write that down.

193
00:09:37,660 --> 00:09:40,216
And that's going to tell us how
many moles of oxygen we're

194
00:09:40,216 --> 00:09:41,060
going to need.

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00:09:41,060 --> 00:09:43,810
And, remember, we want to get
rid of these moles of glucose.

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00:09:43,810 --> 00:09:45,565
So we want to write that
in the denominator.

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00:09:45,565 --> 00:09:49,870


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00:09:49,870 --> 00:09:56,490
So moles of glucose required.

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00:09:56,490 --> 00:10:00,600
For every 1 mole of glucose
required, we figured out when

200
00:10:00,600 --> 00:10:03,680
we balanced out the equation,
for every mole of glucose, we

201
00:10:03,680 --> 00:10:06,510
need 6 moles of oxygen.

202
00:10:06,510 --> 00:10:13,060
We need 6 moles of
O2 required.

203
00:10:13,060 --> 00:10:16,360
And then what do we get here?

204
00:10:16,360 --> 00:10:20,190
Well we have the moles of
glucose canceling out with the

205
00:10:20,190 --> 00:10:21,750
moles of glucose.

206
00:10:21,750 --> 00:10:26,180
And then we multiply
the 6 times 0.139.

207
00:10:26,180 --> 00:10:32,850
So let's just multiply this
times 6 is equal to 0.833.

208
00:10:32,850 --> 00:10:38,770
So we need 0-- that's
too fat-- 0.833

209
00:10:38,770 --> 00:10:43,330
moles of oxygen required.

210
00:10:43,330 --> 00:10:47,720
Now, we're almost there, we know
how many moles of oxygen

211
00:10:47,720 --> 00:10:49,610
are required, molecular
oxygen.

212
00:10:49,610 --> 00:10:52,130
Now we just have to figure out
how many grams that is.

213
00:10:52,130 --> 00:10:53,820
So let me just write
it over here.

214
00:10:53,820 --> 00:11:01,850
We have 0.833 moles of molecular
oxygen are required.

215
00:11:01,850 --> 00:11:04,010
We're going to multiply that.

216
00:11:04,010 --> 00:11:07,470
Remember, we want to get
this into grams now.

217
00:11:07,470 --> 00:11:10,570
So let's try the moles of
O2 in the denomenator.

218
00:11:10,570 --> 00:11:13,350


219
00:11:13,350 --> 00:11:17,090
And we're going to put grams
of O2 in the numerator.

220
00:11:17,090 --> 00:11:21,300
So how many grams of O2
are there per mole?

221
00:11:21,300 --> 00:11:24,980
Well, we know the atomic
weight oxygen is 16.

222
00:11:24,980 --> 00:11:27,460
So the atomic weight of
molecular oxygen, where you

223
00:11:27,460 --> 00:11:33,520
have two of these, is equal
to 16 times two.

224
00:11:33,520 --> 00:11:36,400
Which is equal to 32.

225
00:11:36,400 --> 00:11:42,640
So it's 32 grams per mole.

226
00:11:42,640 --> 00:11:46,400
So when we perform the
calculation, the moles of O2

227
00:11:46,400 --> 00:11:48,950
in the numerator cancel out
with moles of O2 in the

228
00:11:48,950 --> 00:11:49,680
denomenator.

229
00:11:49,680 --> 00:11:59,750
And we're just going to have
0.833 times 32 is equal to

230
00:11:59,750 --> 00:12:02,940
26-- I'll just say, seven.

231
00:12:02,940 --> 00:12:09,570
So this is equal to 26.7
grams of O2 required.

232
00:12:09,570 --> 00:12:13,650
Grams of O2, and I'll
write required in

233
00:12:13,650 --> 00:12:15,650
that same exact collar.

234
00:12:15,650 --> 00:12:17,940
So we finished one part
of the question.

235
00:12:17,940 --> 00:12:20,830
We have two more parts left.

236
00:12:20,830 --> 00:12:25,180
If we go back to the problem, it
asks us, we already figured

237
00:12:25,180 --> 00:12:27,680
out, what mass of oxygen
is required for

238
00:12:27,680 --> 00:12:28,470
the complete reaction?

239
00:12:28,470 --> 00:12:31,500
We did that part, so we can
write a little check there.

240
00:12:31,500 --> 00:12:32,500
We did that first part.

241
00:12:32,500 --> 00:12:36,690
But they also ask, what masses
of carbon dioxide and water

242
00:12:36,690 --> 00:12:37,490
are formed?

243
00:12:37,490 --> 00:12:41,410
So now we need to figure out
carbon dioxide and water.

244
00:12:41,410 --> 00:12:43,800
And so we go back here.

245
00:12:43,800 --> 00:12:47,930
We know we have 0.139
moles of glucose.

246
00:12:47,930 --> 00:12:50,550
We figured that out
in the first part.

247
00:12:50,550 --> 00:12:58,350
So 0.139 moles of glucose.

248
00:12:58,350 --> 00:13:05,140
And let's do the carbon dioxide
first. We know for

249
00:13:05,140 --> 00:13:09,940
every mole of glucose, we're
going to produce 6 moles of

250
00:13:09,940 --> 00:13:10,770
carbon dioxide.

251
00:13:10,770 --> 00:13:11,670
We see that right there.

252
00:13:11,670 --> 00:13:13,560
There's a one out
here implicitly.

253
00:13:13,560 --> 00:13:17,380
So for every mole of glucose,
you're going to produce 6

254
00:13:17,380 --> 00:13:19,290
moles of carbon dioxide.

255
00:13:19,290 --> 00:13:21,130
So let's write that.

256
00:13:21,130 --> 00:13:29,040
So for every one mole of
glucose, you're going to have

257
00:13:29,040 --> 00:13:34,660
6 moles of CO2 produced.

258
00:13:34,660 --> 00:13:36,780
We just got that directly
from the equation.

259
00:13:36,780 --> 00:13:39,710
And I wrote it this way, instead
of one over the 6,

260
00:13:39,710 --> 00:13:41,980
because I wanted it to cancel
out with the moles of glucose.

261
00:13:41,980 --> 00:13:45,050
Moles of glucose in the
numerator, moles of glucose in

262
00:13:45,050 --> 00:13:46,920
the denominator.

263
00:13:46,920 --> 00:13:48,870
So that canceled
out with that.

264
00:13:48,870 --> 00:13:55,960
And this is going to be
equal to 6 times 0.139

265
00:13:55,960 --> 00:14:01,840
moles of CO2 produced.

266
00:14:01,840 --> 00:14:04,810


267
00:14:04,810 --> 00:14:05,710
And we know what that is.

268
00:14:05,710 --> 00:14:09,040
We already multiplied 6
times 0.139 before.

269
00:14:09,040 --> 00:14:17,300
This is going to be equal to
0.833 moles of CO2 produced.

270
00:14:17,300 --> 00:14:19,790
We've already done
that calculation.

271
00:14:19,790 --> 00:14:22,960
And actually we could even--
well, I won't skip too many

272
00:14:22,960 --> 00:14:29,120
steps-- but we see over here,
for every one mole of glucose,

273
00:14:29,120 --> 00:14:32,890
6 moles of this, 6 moles of
this, and 6 moles of that.

274
00:14:32,890 --> 00:14:38,850
So that's why we had the
0.833 moles of oxygen.

275
00:14:38,850 --> 00:14:43,570
And we're also getting the 0.833
moles of carbon dioxide.

276
00:14:43,570 --> 00:14:46,300
And, if we did the exact same
thing, we've performed the

277
00:14:46,300 --> 00:14:47,480
exact same calculation.

278
00:14:47,480 --> 00:14:49,515
For every mole of this
used, you have a

279
00:14:49,515 --> 00:14:50,580
mole of that produced.

280
00:14:50,580 --> 00:14:53,180
Or every 6 of this, you have
6 of that, 6 of that.

281
00:14:53,180 --> 00:14:55,510
So you're also going to have,
by the very same logic, I

282
00:14:55,510 --> 00:14:57,470
mean, you could do this
again with the water.

283
00:14:57,470 --> 00:15:06,980
You're also going to have 0.833
moles of water produced.

284
00:15:06,980 --> 00:15:07,270
Right?

285
00:15:07,270 --> 00:15:09,330
For every mole of carbon
dioxide, you

286
00:15:09,330 --> 00:15:10,100
have a mole of water.

287
00:15:10,100 --> 00:15:12,620
Here it's 6 for 6, but
it's a 1:1 ratio.

288
00:15:12,620 --> 00:15:14,530
You could think about
it like that.

289
00:15:14,530 --> 00:15:18,710
Now let's figure out how
many grams this is.

290
00:15:18,710 --> 00:15:20,920
We have the same number of moles
of carbon dioxide and

291
00:15:20,920 --> 00:15:23,330
the same number of
moles of water.

292
00:15:23,330 --> 00:15:26,400
But they're going to have
different number of grams. So

293
00:15:26,400 --> 00:15:30,340
the actual number of molecules
are the same, but the actual

294
00:15:30,340 --> 00:15:32,480
mass of those molecules are
going to be different.

295
00:15:32,480 --> 00:15:39,950
So what's carbon dioxide's
atomic weight?

296
00:15:39,950 --> 00:15:41,410
Just to remind ourselves.

297
00:15:41,410 --> 00:15:45,520
Carbon has atomic weight
of 12, oxygen of 16.

298
00:15:45,520 --> 00:15:50,810
So it's going to be 12 plus 16
times two, which is equal to

299
00:15:50,810 --> 00:15:55,510
12 plus 32, which
is equal to 44.

300
00:15:55,510 --> 00:16:06,370
So if we are starting off with
0.833 moles of carbon dioxide

301
00:16:06,370 --> 00:16:09,550
that are produced, we want to
figure out how many grams per

302
00:16:09,550 --> 00:16:12,320
mole-- we're going to put the
moles of carbon dioxide in the

303
00:16:12,320 --> 00:16:15,220
denominator because we want
it to cancel with that.

304
00:16:15,220 --> 00:16:18,360
And then we have the grams
of carbon dioxide.

305
00:16:18,360 --> 00:16:21,090
We know carbon dioxide's
atomic weight is 44.

306
00:16:21,090 --> 00:16:24,510
So that means there are 44
grams. If we have a mole of

307
00:16:24,510 --> 00:16:27,620
carbon dioxide, if we have
6.022 times 10 to the 23

308
00:16:27,620 --> 00:16:29,680
carbon dioxide molecules.

309
00:16:29,680 --> 00:16:34,590
So this is going to
be 44 times 0.833

310
00:16:34,590 --> 00:16:38,130
is-- what do we get?

311
00:16:38,130 --> 00:16:46,500
0.833 times 44 is equal to 36
point-- let's just say, 7.

312
00:16:46,500 --> 00:16:56,220
36.7 grams of CO2 are going
to be produced.

313
00:16:56,220 --> 00:16:57,530
And then we're almost done.

314
00:16:57,530 --> 00:17:00,380
We just have to figure out how
many grams of water are going

315
00:17:00,380 --> 00:17:01,040
to be produced.

316
00:17:01,040 --> 00:17:02,590
We know it's the same number
of moles, but how

317
00:17:02,590 --> 00:17:04,329
many grams is that?

318
00:17:04,329 --> 00:17:11,470
So water's atomic weight is
going to be 2 times 1, right?

319
00:17:11,470 --> 00:17:13,460
Because we have to
2 hydrogens.

320
00:17:13,460 --> 00:17:15,839
Plus 16.

321
00:17:15,839 --> 00:17:18,500
Which is equal to 18.

322
00:17:18,500 --> 00:17:26,160
So if we're starting off with
0.833 moles, or if we're

323
00:17:26,160 --> 00:17:33,680
producing 0.833 moles of water,
we just multiply that

324
00:17:33,680 --> 00:17:36,920
times how many grams
per mole of water?

325
00:17:36,920 --> 00:17:41,200
So 1 mole of H2O-- once again
we want this in the

326
00:17:41,200 --> 00:17:45,110
denominator so it cancels out
with this in the numerator.

327
00:17:45,110 --> 00:17:51,990
1 mole of H20 has a mass of 18
grams. Or 18 grams of H20 for

328
00:17:51,990 --> 00:17:53,700
every mole of H20.

329
00:17:53,700 --> 00:17:59,510
So this cancels with that and
we get-- get the calculator

330
00:17:59,510 --> 00:18:13,180
out-- 18 times 0.833
is equal to 14.994.

331
00:18:13,180 --> 00:18:16,630
So we can just round
that to 15.0.

332
00:18:16,630 --> 00:18:25,230
So we have 15.0 grams
of water produced.

333
00:18:25,230 --> 00:18:27,200
And we're done!

334
00:18:27,200 --> 00:18:28,520
We are done.

335
00:18:28,520 --> 00:18:34,910
We figured out that if we start
off with that 25 grams

336
00:18:34,910 --> 00:18:37,180
of glucose, like they told us
at the beginning of the

337
00:18:37,180 --> 00:18:42,600
problem, we're going to require
26.7 grams of oxygen

338
00:18:42,600 --> 00:18:46,740
to react with it, we're going
to produce 36.7 grams of

339
00:18:46,740 --> 00:18:52,180
carbon dioxide, and
15 grams of water.