Chemical Bonding: C₂H₆ Lewis Structure

Drawing the Lewis Structure for C₂H₆ - Ethane

Viewing Notes:

• With C₂H₆ there are only single bonds. Whenever you see a compound made of Carbon and Hydrogen that ends in ane that means it will only have single bonds.
• Remember that Hydrogen (H) atoms always go on the outside of a Lewis Structure.
• Note that Hydrogen only needs two valence electrons to have a full outer shell.

Transcript: Hi, this is Dr. B. Let's do the Lewis structure for C2H6, ethane. On the periodic table, Carbon is in group 4 or 14, so it has 4 valence electrons, but we have 2 of them. So let's multiply that times 2. And then Hydrogen, group 1, one valence electron; we have 6, multiply that by 6, for a total of 14 valence electrons to work with. Hydrogen always goes on the outside, so we'll draw our Carbons. And then we'll put the six Hydrogens: 1, 2, 3, 4, 5, 6 Hydrogens around there.

So we're going to take and put some valence electrons. Let's first form the central bond, that's 2 valence electrons. Then the outer bonds here, remember Hydrogen only needs 2 for an octet. So we've just filled the octet there. So we have 2, 4, 6, 8, 10, 12, 14 valence electrons. We've used them all up. Let's take a look and see if we have octets. We know the Hydrogens are fine with two. Carbon, 2, 4, 6, 8; and this Carbon also has 8. So that is the Lewis structure for ethane, C2H6.

We can also draw it as a structural formula, and you'll see this quite frequently. That'll look like this here, where these lines represent a pair of electrons, a chemical bond.

This is Dr. B., and thanks for watching.