Drawing the Lewis Structure for CH2F2 (Difluoromethane)

Viewing Notes:

  • The Lewis structure for CH2F2 is similar to CF2Cl2. The difference is that you have H and F in this Lewis structure.
  • Remember that Hydrogen only needs 2 valence electrons for a full outer shell.
  • For the CH2F2 Lewis structure there are a total of 20 valence electrons available.

Transcript: Hi, this is Dr. B. Let's do the Lewis structure for CH2F2: difluoromethane. On the periodic table, Carbon is in group 4, it has 4 valence electrons. Hydrogen, group 1, but we have 2 Hydrogens. Fluorine, 7 valence electrons, we have 2 of those as well, for a total of 20 valence electrons. We'll put the Carbon at the center, and then Hydrogens always go on the outside. And the Fluorines are very electronegative so they go on the outside, as well.

We'll start by putting two valence electrons between each of the atoms to form a chemical bond, and that's used up 2, 4, 6, 8. We have 20. Let's go around the outside: 10, 12, 14, 16, 18, 20. So we've used all the valence electrons. Let's see if we have octets. Hydrogen only needs two valence electrons, so it's OK. Fluorine needs 8, this Fluorine has 8 and this Fluorine has 8. And then Carbon, in the center, needs 8, and it has 8. So we've used all the valence electrons. Everything has full outer shells.

That is the Lewis structure for CH2F2. This is Dr. B., and thanks for watching.