Q36E. - Organic Chemistry (Mcmurry)

Question

What kind of hybridization do you expect for each carbon atom in the following molecules?

(a) ${\mathbf{CH}}_{\mathbf{3}}{\mathbf{CH}}_{\mathbf{2}}{\mathbf{CH}}_{\mathbf{3}}$

(b) 2-methylpropene

(c) But-1-en-3-yne ${\mathbf{H}}_{\mathbf{2}}\mathbf{C}\mathbf{=}\mathbf{CH}\mathbf{-}\mathbf{C}\equiv \mathbf{CH}$

(d) Acetic acid

Step-by-Step Solution

Answer

(a)

                       Hybridization of carbons in propane

(b)

                               Hybridization of carbons in But-1-en-3-yne

(c) 

                               Hybridisation of 2 methyl propene

(d)

                               Hybridization of carbons in acetic acid

Hybridization

Hybridization is the mixing of atomic orbital of different energies or shapes to form a new hybrid orbital that helps in the pairing of electrons and the formation of chemical bonds according to valence bond theory.

Concept of hybridization

The table depicted below summarizes the hybridization of different types of bonds formed

$$\begin{gathered} \mathrm{Bonds} \mathrm{formed} \mathrm{Hybridization} \\ 4 \mathrm{single} \mathrm{bonds} {\mathrm{sp}}^3 \\ 2 \mathrm{single} \mathrm{bonds} \mathrm{and} 1\mathrm{double} \mathrm{bond} {\mathrm{sp}}^2 \\ 1 \mathrm{single} \mathrm{bond} \mathrm{and} 1\mathrm{triple} \mathrm{bond} \mathrm{sp} \\ 2\mathrm{double} \mathrm{bonds} \mathrm{sp} \end{gathered}$$

Hybridization of carbons in propane

All the carbon atoms of propane are forming single bonds with hydrogen. Thus, all carbon atoms of propane are hybridized. The structure for propane is 

(a)

                                      Hybridization of carbons in propane

2-methyl propene has two different types of carbon. Of which two carbons bonded to three hydrogen atoms are hybridized and two other carbons hybridized. The structure of 2-methylpropene is:

(b) 

                                       Hybridization of carbons in 2-methylpropene

But-1-en-3-yne has two type of hybridized carbon. Of which two carbons are hybridized and the remaining two are hybridized. The structure of but-1-en-3-yne is

(c)

                                          Hybridization of carbons in But-1-en-3-yne

Acetic acid has two types of hybridized carbons. One carbon is hybridized and the other carbon is hybridized respectively. The structure of acetic acid is:

(d)

                                             Hybridization of carbons in acetic acid