## Fall 2014 Midterm #8

$sp, sp^{2}, sp^{3}, dsp^{3}, d^{2}sp^{3}$

Shirley Wong 2E
Posts: 22
Joined: Fri Sep 25, 2015 3:00 am

### Fall 2014 Midterm #8

The question is: Consider the bonding in: CH2=CHCHO. Identify the composition of each bond and the hybridization of each lone pair. For the double bonds, why is the composition of the pi bond different from the sigma bond? For example, for the double bond between two C atoms, the sigma bond is (C2sp2, C2sp2), but the pi bond is (C2p, C2p). Shouldn't the pi bond be the same as the sigma bond because it still contains the same atoms with the same hybridizations?

Chem_Mod
Posts: 17489
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 393 times

### Re: Fall 2014 Midterm #8

A double bond consists of one sigma bond and one pi bond, and by definition they are different. Hybridization is a property of the atoms and not the bonds. The C atoms are sp2 hybridized, resulting in 3 hybrid orbitals and 1 unhybridized p-orbital for each C

2 hybrid orbitals bond to either H or the group CHO
1 hybrid orbital overlaps the one on the other C for the C-C sigma
the unhybridized p-orbital overlaps the one on the other C for the C-C pi