Drawing the Lewis Structure for COH2

Viewing Notes:

  • In COH2 Lewis structure Carbon is less electron electronegative than Oxygen and goes in the center of the Lewis structure (note that Hydrogen atoms always go on the outside).
  • For the COH2 Lewis structure Hydrogen only needs two valence electrons for a full outer shell.
  • In the Lewis structure for COH2 there are a total of 12 valence electrons.
  • You'll need to form a double bond between the Carbon and Oxygen to complete the octet on the Carbon.

Transcript: This is the COH2 Lewis structure. On the periodic table, Carbon is in group 4, it has 4 valence electrons. Oxygen, group 6, 6 valence electrons; and Hydrogen, group 1, but we have two of those, so we'll multiply that by 2. Four plus 6 plus 2:12 valence electrons. Hydrogens always go on the outside, and then we'll put Carbon in the middle. Carbon's the least electronegative, so that's a good place for it. We'll put the Oxygen here, and then we have two Hydrogens, like this. We'll put two electrons between atoms to form chemical bonds, so we've used 6. Hydrogen only needs two valence electrons, so its octet is full. So 2, 4, 6, and then around the Oxygen, 8, 10, 12 to give that an octet.

So we've used all 12 of the valence electrons. At this point, the Hydrogens both have two valence electrons, so their outer shell is full, and the Oxygen has 8, so it has an octet. But the Carbon only has 6. So it does not have a full outer shell. What we can do is take two of these electrons here from the Oxygen and share them with the Carbon. So by creating that double bond, Oxygen still has 8 valence electrons, but now Carbon also has 8 valence electrons. So we've used all 12 valence electrons, and each of the atoms has a full outer shell.

So this is the Lewis structure for COH2. This is Dr. B., and thanks for watching.