What makes something sp2 hybridized

Click here to Register! By joining Chemistry Steps, you will gain instant access to the answers and solutions for all the Practice Problems including over 20 hours of problem-solving videos, Multiple-Choice Quizzes, Puzzles, and t he powerful set of Organic Chemistry 1 and 2 Summary Study Guides. For each marked atom, add any missing lone pairs of electrons to determine the steric number, electron and molecular geometry, approximate bond angles and hybridization state:.

Notify me of followup comments via e-mail. You can also subscribe without commenting. Some exceptions There a few common exceptions to what we have discussed about determining the hybridization state and they are mostly related to the method where we look at the bonding type of the atom.

Another common, and very important example is the carbocations. An exception to the Steric Number method One exception with the steric number is, for example, the amides. Hint: Remember to add any missing lone pairs of electrons where necessary. This content is for registered users only. Remember Me. Forgot Password. Take a Quiz Now. Boundless vets and curates high-quality, openly licensed content from around the Internet. This particular resource used the following sources:.

Skip to main content. Advanced Concepts of Chemical Bonding. Search for:. Learning Objective Recognize the role of sp 2 hybridized atoms in sigma and pi bonding. We can go ahead and draw in an SP2 hybrid orbital and there's one electron in that orbital and then there's another one with one electron and then here's another one with one electron.

This carbon being SP2 hybridized also has an unhybridized P orbital with one electron. Go ahead and draw in that P orbital with its one electron. We also have some hydrogens. We have some hydrogens to think about here. Each carbon is bonded to two hydrogens. Let me go ahead and put in the hydrogens. The hydrogen has a valance electron in an unhybridized S orbital.

I'm going ahead and putting in the S orbital and the one valance electron from hydrogen like this. When we take a look at what we've drawn here, we can see some head on overlap of orbitals, which we know from our earlier video is called a sigma bond. Here's the head on overlap of orbitals. That's a sigma bond. The carbon carbon bond, here's also a head on overlap of orbitals and then we have these two over here.

We have a total of five sigma bonds in our molecules. Let me go ahead and write that over here. There are five sigma bonds. If I would try to find those on my dot structure this would be a sigma bond. This would be a sigma bond. One of these two is a sigma bond and then these over here. A total of five sigma bonds and then we have a new type of bonding.

These unhybridized P orbitals can overlap side by side. Up here and down here. We get side by side overlap of our P orbitals and this creates a pi bond. A pi bond, let me go ahead and write that here. A pi bond is side by side overlap. There is overlap above and below this sigma bond here and that's going to prevent free rotation.

When we're looking at the example of ethane, we have free rotation about the sigma bond that connected the two carbons but because of this pi bond here, this pi bond is going to prevent rotations so we don't get different confirmations of the ethylene molecules. No free rotation due to the pi bonds. When you're looking at the dot structure, one of these bonds is the pi bonds, I'm just gonna say it's this one right here. If you have a double bond, one of those bonds, the sigma bond and one of those bonds is a pi bond.

We have a total of one pi bond in the ethylene molecule. If you're thinking about the distance between the two carbons, let me go ahead and use a different color for that. The distance between this carbon and this carbon. It turns out to be approximately 1. Remember for ethane, the distance was approximately 1. A double bond is shorter than a single bond. One way to think about that is the increased S character. This increased S character means electron density is closer to the nucleus and that's going to make this lobe a little bit shorter than before and that's going to decrease the distance between these two carbon atoms here.

Let's look at the dot structure again and see how we can analyze this using the concept of steric number. Let me go ahead and redraw the dot structure. We have our carbon carbon double bond here and our hydrogens like that. If you're approaching this situation using steric number remember to find the hybridization. We can use this concept. Steric number is equal to the number of sigma bonds plus number of lone pairs of electrons.

If my goal was to find the steric number for this carbon. I count up my number of sigma bonds. That's one, two and then I know when I double bond one of those is sigma and one of those is pi. One of those is a sigma bond. A total of three sigma bonds. I have zero lone pairs of electrons around that carbon. Three plus zero, gives me a steric number of three. I need three hybrid orbitals and we've just seen in this video that three SP2 hybrid orbitals form if we're dealing with SP2 hybridization.

If we get a steric number of three, you're gonna think about SP2 hybridization. One S orbital and two P orbitals hybridizing. That carbon is SP2 hybridized and of course, this one is too.