- [Instructor] In a previous video,
we used a particulate model like this
to understand a reaction,
not just to understand the reaction,
but to balance the
chemical reaction as well.
And when I hand drew these particles,
the atoms in this particulate model here,
I tried to draw it pretty close
to their actual relative sizes.
Carbon atoms are a little
bit bigger than oxygen atoms,
and they're both a lot
bigger than hydrogen atoms.
What we're gonna do in this video
is extend our understanding
using a particulate model
to start to visualize
what actually might go on
in a mixture
of some of these reactant molecules.
So what I have here on the left-hand side
are the various molecules.
I have two methane molecules here.
I have three water molecules.
And what I wanna do with you
is draw what we would expect
to see after the reaction.
And I encourage you, like
always, pause this video
and see if you can have a go at that,
maybe with a pencil and paper,
at least just try to
imagine it in your head,
before I do this with you.
All right, now, let's do this together.
Now, we know that for every
methane and every water,
we're going to produce one carbon monoxide
and three molecular hydrogens.
And each of those molecules of hydrogen
have two hydrogens in them.
So let's just say that this
one and this one react.
They're going to produce
one carbon monoxide.
I'm gonna try to draw the
relative sizes roughly, right?
So one carbon monoxide.
And then they're gonna
produce six hydrogen atoms
that are going to be in
three hydrogen molecules.
So let's do,
that's two and four,
and then I'll just do one here
and then six.
All right, so I took care
of this one and this one.
And now we can imagine that
maybe this water molecule
reacts with this methane molecule,
and so that would produce
another carbon monoxide.
Let me draw that
roughly at the right size.
Another carbon monoxide molecule
and three more hydrogen molecules
for a total of six more hydrogens.
So that's one and two
and three.
And now we have this water right over here
that had no one to react
with in this situation,
had no partner.
And so that's just going to be
a leftover reactant molecule.
So let me just draw it right over here.
So that water could be
right over right over here.
And so this was a useful way
of starting to visualize
what might be going on.
Remember, this is happening
at a very high temperature.
They're all bouncing around, et cetera.
And then when they react,
you might get this,
but then this water molecule
has no one to react to,
so it is, you could view it as a leftover
after the reaction.