Number of sigma and pi bonds

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Julia Lindner 1I
Posts: 35
Joined: Fri Sep 28, 2018 12:17 am

Number of sigma and pi bonds

Postby Julia Lindner 1I » Sun Nov 25, 2018 9:53 pm

Can someone explain how to figure out the number of sigma and pi bonds in a molecule just by knowing the number of hybridized orbitals on the central atom? For example, in problem 2F.3 I know that the central atom, S, has four hybridized sp3 orbitals. How do I know the sigma/pi bonds from that?

Katie_Duong_1D
Posts: 69
Joined: Fri Sep 28, 2018 12:27 am

Re: Number of sigma and pi bonds

Postby Katie_Duong_1D » Sun Nov 25, 2018 10:30 pm

The number of electron densities should equal the number of sigma pi bonds. If there are 4 regions of electron density (AX4, for example), then the sp hybridization would be sp3.

305117729
Posts: 30
Joined: Fri Sep 28, 2018 12:16 am

Re: Number of sigma and pi bonds

Postby 305117729 » Sun Nov 25, 2018 11:33 pm

There is an easy way to count sigma and pi bonds. One single bond is one sigma bond, and one double bond consists of one sigma bond and one pi bond, a triple bond one sigma bond and two pi bonds. So if you simply want to know the number of each bond, you could just count the number of single, double, and triple bond, then do a easy calculation.

MichelleRamirez_2F
Posts: 63
Joined: Fri Sep 28, 2018 12:28 am

Re: Number of sigma and pi bonds

Postby MichelleRamirez_2F » Tue Dec 04, 2018 9:28 pm

You would still have to draw the Lewis structure ( with help of the hybridization) to see whether the bonds are single, double and triple bonds. Once you know the structure the number of sigma bonds are the number of. single bonds and the pi bonds are any bonds starting from the second bond. This means that if you have a triple bond the first bond is a sigma bond and the second and third bond are pi bonds.

Mark 1D
Posts: 63
Joined: Fri Sep 28, 2018 12:18 am

Re: Number of sigma and pi bonds

Postby Mark 1D » Fri Dec 07, 2018 8:21 pm

a single bond corresponds to a sigma bond, whilst a double bond is 1 sigma and 1 pi and a triple bond is 1 sigma and 2 pis

Jacqueline Duong 1H
Posts: 61
Joined: Fri Sep 28, 2018 12:28 am

Re: Number of sigma and pi bonds

Postby Jacqueline Duong 1H » Sun Dec 09, 2018 8:37 pm

To count the number of sigma and pi bonds there are, a single bond would be sigma, a double bound would be a pi bond and sigma bond and a triple bond would be one sigma bond and 2 pi bonds.


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