Hi, this is Dr. B.
We're going to do the Lewis structure for
CF2Cl2, dichlorodifluoromethane.
Let's start out by looking at the periodic
table.
Carbon's in group 4, so it has 4 valence electrons.
Fluorine, group 7, sometimes called 17, but
we have two of those so let's multiply that
times 2.
Plus Chlorine is in group 7, and then we've
got two of those, as well.
If you add that up you have a total of 32
valence electrons to work with.
Let's take and draw this.
We'll put Carbon, the least electronegative,
right at the center.
And then let's put Fluorines on either side,
make it symmetrical here.
And then we'll put Chlorines on the other
side.
So there you go, that is the skeleton of this
thing.
And we're going to put some electrons around
each of the atoms.
Let's put two here, two here, two here, and
two here.
We've used eight.
We've formed chemical bonds there.
Now let's do the outside.
So we have 8, 10, 12, 14, 16, 18, 20, 22,
24, 26, 28, 30, and 32.
And that's really nice because we have 32
that we started with.
Let's check and see if we have full octets
here.
So Carbon needs 8 and Carbon does have 8.
And then each of these other ones right here
has 8 as well, so it has an octet or a full
outer shell.
And we've only used 32 valence electrons like
we started with.
That is the Lewis structure for CF2Cl2.
You could also draw it like this right here
as a structural formula, and you'll see that
sometimes, as well.
This is Dr. B., thank you for watching.
