WEBVTT
1
00:00:00.140 --> 00:00:02.899 A:middle L:90%
So before I begin this video, I wanted Thio
2
00:00:02.910 --> 00:00:06.320 A:middle L:90%
briefly correct myself in last video eso last time I
3
00:00:06.320 --> 00:00:10.750 A:middle L:90%
think I reported water in five significant figures, but
4
00:00:10.759 --> 00:00:14.449 A:middle L:90%
it should be four significant figures eso this video I
5
00:00:14.449 --> 00:00:19.170 A:middle L:90%
will be using the value 0.1723 miles, Right?
6
00:00:19.199 --> 00:00:23.589 A:middle L:90%
So last time we figured out how to calculate the
7
00:00:23.589 --> 00:00:28.160 A:middle L:90%
molar mass of the different molecules in this combustion reaction
8
00:00:28.170 --> 00:00:32.009 A:middle L:90%
of sugar. And we've also figured out how to
9
00:00:32.009 --> 00:00:36.280 A:middle L:90%
calculate to the number of moles of each molecule given
10
00:00:36.280 --> 00:00:39.679 A:middle L:90%
the mass of sugar. And so in this video
11
00:00:39.689 --> 00:00:43.630 A:middle L:90%
will be learning how to calculate the number of particles
12
00:00:43.640 --> 00:00:46.170 A:middle L:90%
or, in this case, the number of molecules
13
00:00:46.539 --> 00:00:51.890 A:middle L:90%
, um that are produced in this reaction based off
14
00:00:51.899 --> 00:00:56.219 A:middle L:90%
of the previous information from the last video. And
15
00:00:56.219 --> 00:00:59.409 A:middle L:90%
so we can do this by using avocados number.
16
00:00:59.420 --> 00:01:00.960 A:middle L:90%
And you might remember this, um, in the
17
00:01:00.960 --> 00:01:06.299 A:middle L:90%
dimensional analysis video that I did previously. So Allah
18
00:01:06.299 --> 00:01:07.659 A:middle L:90%
, God Rose number just all right. On the
19
00:01:07.659 --> 00:01:15.560 A:middle L:90%
side is six point 0 to 2 times 10 to
20
00:01:15.569 --> 00:01:26.140 A:middle L:90%
the 23rd particles Permal and avocados. Number is basically
21
00:01:26.150 --> 00:01:30.019 A:middle L:90%
a way for us to convert moles to number of
22
00:01:30.019 --> 00:01:34.739 A:middle L:90%
particles on DSO will be using this to calculate the
23
00:01:34.739 --> 00:01:38.959 A:middle L:90%
number of molecules given the number of moles for all
24
00:01:38.959 --> 00:01:41.829 A:middle L:90%
of these molecules. So to do this we'll be
25
00:01:41.829 --> 00:01:45.230 A:middle L:90%
using dimensional analysis again. And so we could do
26
00:01:45.230 --> 00:01:49.120 A:middle L:90%
this by beginning to write the value that were given
27
00:01:49.129 --> 00:01:53.530 A:middle L:90%
first. So here we're working with the moles that
28
00:01:53.530 --> 00:01:57.950 A:middle L:90%
we calculated from before, and you calculate the number
29
00:01:57.950 --> 00:02:00.849 A:middle L:90%
of molecules, Um, in the given number of
30
00:02:00.849 --> 00:02:05.310 A:middle L:90%
moles will be multiplying This by Allah. God,
31
00:02:05.310 --> 00:02:12.389 A:middle L:90%
Rose number has shown here, and I don't have
32
00:02:12.389 --> 00:02:14.710 A:middle L:90%
all of states. So I'm not gonna write particles
33
00:02:14.719 --> 00:02:16.750 A:middle L:90%
, but make sure that you keep in mind that
34
00:02:16.750 --> 00:02:20.219 A:middle L:90%
this is in particles. And so again, if
35
00:02:20.219 --> 00:02:23.270 A:middle L:90%
we use dimensional analysis, we can cross off the
36
00:02:23.270 --> 00:02:27.150 A:middle L:90%
bulls. And is this ensures that we have the
37
00:02:27.150 --> 00:02:30.050 A:middle L:90%
right answer, which is a number of particles.
38
00:02:30.060 --> 00:02:31.569 A:middle L:90%
And so what do we do out the math?
39
00:02:32.840 --> 00:02:44.229 A:middle L:90%
We should get nine 0.430 times 10 to the 21st
40
00:02:44.379 --> 00:02:53.849 A:middle L:90%
molecules. And so, given 0.1566 moles of sugar
41
00:02:53.340 --> 00:02:58.110 A:middle L:90%
, we have 9.430 times 10 to the 21st molecules
42
00:02:58.150 --> 00:03:00.620 A:middle L:90%
using avocados number and again, you can do the
43
00:03:00.620 --> 00:03:06.659 A:middle L:90%
same thing for oxygen, carbon dioxide and water.
44
00:03:07.340 --> 00:03:09.270 A:middle L:90%
And so we already accounted for the fact that they're
45
00:03:09.270 --> 00:03:14.259 A:middle L:90%
12 molecules per one molecule of sugar in the previous
46
00:03:14.259 --> 00:03:16.180 A:middle L:90%
problem. So now we just need to multiply this
47
00:03:16.180 --> 00:03:19.669 A:middle L:90%
by Alpha God Rose number. So again, using
48
00:03:19.669 --> 00:03:23.360 A:middle L:90%
dimensional analysis, you can multiply this like so.
49
00:03:23.740 --> 00:03:28.780 A:middle L:90%
And instead of what about the whole thing? I'll
50
00:03:28.780 --> 00:03:37.710 A:middle L:90%
abbreviate this as a hashtag, and so this will
51
00:03:37.719 --> 00:03:46.729 A:middle L:90%
equal 1.132 times 10 to the 23rd. And given
52
00:03:46.729 --> 00:03:50.949 A:middle L:90%
that we're using the same goals for carbon dioxide,
53
00:03:51.340 --> 00:03:59.069 A:middle L:90%
this is also 1.132 times 10 to the 23rd molecules
54
00:04:02.240 --> 00:04:03.830 A:middle L:90%
. And you want to make sure that you always
55
00:04:03.830 --> 00:04:11.759 A:middle L:90%
keep your unit straight. Yeah, raised. Well
56
00:04:12.240 --> 00:04:15.789 A:middle L:90%
, um, you'll be multiplying avocados number by a
57
00:04:15.800 --> 00:04:19.769 A:middle L:90%
different value. And so it would be 0.17 to
58
00:04:19.769 --> 00:04:27.660 A:middle L:90%
3 times all cadres number, which ends up being
59
00:04:29.139 --> 00:04:33.860 A:middle L:90%
1.37 times 10 to the 23rd. And again,
60
00:04:33.860 --> 00:04:39.089 A:middle L:90%
I'm making sure that I'm keeping my significant figures the
61
00:04:39.089 --> 00:04:43.259 A:middle L:90%
same throughout the whole problem. And so now we've
62
00:04:43.259 --> 00:04:47.100 A:middle L:90%
calculated the number of molecules for all the molecules in
63
00:04:47.100 --> 00:04:51.139 A:middle L:90%
this combustion reaction And so now, in addition to
64
00:04:51.139 --> 00:04:55.220 A:middle L:90%
calculating the number of molecules, you can also calculate
65
00:04:55.230 --> 00:04:58.379 A:middle L:90%
the number of atoms. So, for example,
66
00:04:58.420 --> 00:05:00.279 A:middle L:90%
let's say you're given a mass, and you want
67
00:05:00.279 --> 00:05:05.930 A:middle L:90%
to calculate the number off carbon atoms that you're using
68
00:05:05.930 --> 00:05:10.050 A:middle L:90%
in this reaction. So before you can use 3
69
00:05:10.050 --> 00:05:13.699 A:middle L:90%
g that you're given to calculate the moles, and
70
00:05:13.699 --> 00:05:15.790 A:middle L:90%
then you can use that to calculate the number of
71
00:05:15.790 --> 00:05:18.089 A:middle L:90%
molecules for the sugar molecule. So now, if
72
00:05:18.089 --> 00:05:20.970 A:middle L:90%
you want to calculate the number of carbon atoms,
73
00:05:21.339 --> 00:05:25.079 A:middle L:90%
you would basically multiply this by 12 because there are
74
00:05:25.079 --> 00:05:28.259 A:middle L:90%
12 carbon atoms. So if we do this out
75
00:05:28.269 --> 00:05:35.740 A:middle L:90%
, this is me 12 times nine point 430 times
76
00:05:35.740 --> 00:05:41.500 A:middle L:90%
10 to the 21st. And so you would get
77
00:05:42.139 --> 00:05:50.959 A:middle L:90%
1.132 times 10 to the 23rd carbon atoms for sugar
78
00:05:55.040 --> 00:05:57.220 A:middle L:90%
. And so here we can see that you can
79
00:05:57.220 --> 00:06:01.750 A:middle L:90%
use avocados number to calculate the number of atoms or
80
00:06:01.750 --> 00:06:04.649 A:middle L:90%
the number of molecules, depending on which when you're
81
00:06:04.649 --> 00:06:09.639 A:middle L:90%
looking for, by using all of this information,
82
00:06:09.649 --> 00:06:12.490 A:middle L:90%
and this will be very useful when you're trying to
83
00:06:12.490 --> 00:06:16.060 A:middle L:90%
get quantitative information from chemical reactions. And in the
84
00:06:16.060 --> 00:06:18.959 A:middle L:90%
real world, um, we actually use this a
85
00:06:18.959 --> 00:06:24.680 A:middle L:90%
lot in synthetic chemistry because there are some reactions that
86
00:06:24.680 --> 00:06:29.660 A:middle L:90%
require specific ratios off molecules. Thio obtain the number
87
00:06:29.670 --> 00:06:32.740 A:middle L:90%
of product that you want, and so it's important
88
00:06:32.740 --> 00:06:35.439 A:middle L:90%
to understand how to do all of the story count
89
00:06:35.439 --> 00:06:40.089 A:middle L:90%
entry. So you end up not wasting any precious
90
00:06:40.100 --> 00:06:44.449 A:middle L:90%
material to create your product or if you just want
91
00:06:44.449 --> 00:06:47.269 A:middle L:90%
to have a small scale reaction to make sure the
92
00:06:47.269 --> 00:06:49.189 A:middle L:90%
reaction works in the first place and has a good
93
00:06:49.189 --> 00:06:51.069 A:middle L:90%
yield. Or if you want to set up some
94
00:06:51.069 --> 00:06:54.750 A:middle L:90%
kind of reaction on a larger scale because you want
95
00:06:54.740 --> 00:06:58.129 A:middle L:90%
a lot of starting material for something a bit more
96
00:06:58.129 --> A:middle L:90%
complicated.