Hang tight while we fetch the video data and transcripts. This only takes a moment.
Connecting to YouTube player…
Fetching transcript data…
We’ll display the transcript, summary, and all view options as soon as everything loads.
Next steps
Loading transcript tools…
Chapter 7.3b Calculations with Stoichiometry | Michelle Bunagan | YouTubeToText
YouTube Transcript: Chapter 7.3b Calculations with Stoichiometry
Skip watching entire videos - get the full transcript, search for keywords, and copy with one click.
Share:
Video Transcript
Video Summary
Summary
Core Theme
This content explains how to use stoichiometric factors derived from balanced chemical equations to perform calculations involving mass, moles, and molarity, specifically demonstrating conversions between moles of reactants and products, and from moles to molecules.
Mind Map
Click to expand
Click to explore the full interactive mind map • Zoom, pan, and navigate
welcome everyone to the next video in
our last one we learned how to write
stoichiometric factors and in this video
we're going to learn how to use them
we're going to use them to perform
stoichiometric calculations involving
Mass moles and solution molarity
so let's do some examples
in this question we're asked how many
moles of iodine I2 are required to react
with 0.429 moles of aluminum according
to the following equation and we're
given a balanced chemical equation
involving aluminum iodine and those two
react together to form aluminum iodide
and the figure at the bottom shows
pictures of this chemical reaction where
we have the reaction of aluminum and
iodine and you can see that the heat of
the reaction actually vaporizes some of
the solid iodine to generate its purple
Vapor which is kind of cool
so how do we go about doing this
calculation well we're going to use our
stoichiometric Factor we know that our
stoichiometric Factor can relate the
number of moles of aluminum and the
moles of iodine according to the
balanced chemical equation we know that
we can write a stoichiometric factor
from our balanced chemical equation
using the ratios of these two reactants
specifically from our coefficients we
can write that three moles of I2
are needed to react with two moles of aluminum
aluminum
and I'm getting that information from
the coefficients of our balanced
chemical equation
so we know in our question that we want
to react
and we want to use this information to
calculate the moles of iodine and to get
it we're going to use our stoichiometric
Factor now we see that moles of aluminum
need to cancel so we're going to need to
write that part of our stoichiometric
factor in the denominator so we'll have
two moles of aluminum in the denominator
and in the numerator we should have
three moles
of iodine I2
when we do this calculation the moles of
aluminum should cancel and we'll be left
with moles
of I2
and plugging these numbers into a
calculator I get
0.644 so this would be 0.644 moles of I2
would be needed to react with 0.429
moles of aluminum
so now let's do an example that's
slightly more complicated so here we
have how many carbon dioxide molecules
are produced when
0.75 moles of propane is combusted
according to this equation so here we
have a combustion reaction which we've
learned here we see that our fuel
propane is going to be burned in the
presence of oxygen to yield carbon
dioxide and water now our question is
specifically asking us how many carbon
dioxide molecules are going to be
produced when 0.75 moles of propane our
fuel are combusted
now we know that we can relate moles of
propane to moles of carbon dioxide using
our stoichiometric Factor
our question is asking specifically how
many carbon dioxide molecules so once we
figure out how many moles of carbon
dioxide would be produced we need to
convert that from moles of carbon
dioxide to molecules and to do that we
can use Avogadro's number so let's do
our calculation
we have 0.75 moles of propane so that is c3h8
and to get from moles of propane to
moles of carbon dioxide I'm going to use
my stoichiometric factor I can see that
I want moles of propane to cancel so I
will need to put that in my denominator
right so that these cancel and my
stoichiometric Factor should have right
one mole of propane for every three
right moles
of CO2 carbon dioxide as I learned by
looking at the reaction Stoichiometry so
moles of propane should cancel and I'll
be left with moles of carbon dioxide
now my next step is to go from moles of
carbon dioxide to molecules of carbon
dioxide and my figure here tells me that
I can use Avogadro's number
in this case
I'm going to want moles to cancel so
I'll write one mole
of CO2 in my denominator and in my
numerator I'll use Avogadro's number so
6.022 times 10 to the 23rd molecules
and so now moles of CO2 cancel and my
calculation should give me molecules of
CO2 So my answer is 1.4 times 10 to the
24th molecules of CO2 so this tells me
how many molecules will be generated
when we combust 0.75 moles of propane
so next we'll look at more complex
Click on any text or timestamp to jump to that moment in the video
Share:
Most transcripts ready in under 5 seconds
One-Click Copy125+ LanguagesSearch ContentJump to Timestamps
Paste YouTube URL
Enter any YouTube video link to get the full transcript
Transcript Extraction Form
Most transcripts ready in under 5 seconds
Get Our Chrome Extension
Get transcripts instantly without leaving YouTube. Install our Chrome extension for one-click access to any video's transcript directly on the watch page.
