Question

Carbon on the left is the highlighted atom.

Answer the questions below about the highlighted atom in this Lewis structure: Н Н—С—С3 С —Н Н н In how many sigma bonds does the highlighted atom participate? In how many pi bonds does the highlighted atom participate? X What is the orbital hybridization of the highlighted atom?

Answer 1

1. Sigma bonds are the single bonds formed by overlapping of two participating orbitals of two atoms forming bond along the internuclear axis . A simple single bond is a sigma bond.

There are four sigma bonds around the highlighted atom shown as :

----- - D Ć - - - -- tc ² 14 म c = । म

Thus the highlighted atom participates in 4 sigma bonds .

2. A pi bond is formed by sideways overlapping of the participating orbitals of two atoms. Pi bond occurs in multiple bonds where 1 bond out of the multiple bonds is always a sigma bond and the other one/ones are pi bonds . For example in a double bond formed between two atoms , one bond is the sigma bond and the other one is a pi bond . In a triple bond between two atoms, one bond out of the three is a sigma bond while the other two are pi bonds.

Since there is no double or triple bond around the highlighted atom so the highlighted atom does not participate in any pi bond. There are only single bonds around the highlighted atom which are all sigma bonds . Thus the highlighted atom participates in 0 pi bonds.

3. The hybridisation of carbon can be sp, sp^{​​​​​2} or sp^{​​​​​3} .

When all four valence orbitals of carbon ( one 2s and three 2p) hybridise to form four sigma bonds around carbon then it is sp³ hybridisation.

When only 3 of the four valence orbitals of carbon hybridise to form three sigma bonds and one of the three 2p orbitals remain unhybridised for sideways overlapping to form a pi bond or remains vacant or has a lone pair of electrons in it then the carbon atom is said to have sp​^{​​​​​2} hybridisation.

When only 2 of the four valence orbitals of carbon hybridise to form 2 sigma bonds and two of the three 2p orbitals remain unhybridised to form pi bonds or remain vacant or contain lone pair of electrons then carbon has sp hybridisation.

Since the highlighted atom ,that is carbon has 4 sigma bonds around it so it is sp^{​​​​​3} hybridised.

Thus the orbital hybridisation of the highlighted atom is sp^{​​​​​3} .