Question

Many important compounds in the chemical industry are derivatives of ethylene $\mathbf{\left(}{\mathbf{C}}_{\mathbf{2}}{\mathbf{H}}_{\mathbf{4}}\mathbf{\right)}$ . Two of them are acrylonitrile and methyl methacrylate.

Complete the Lewis structures for these molecules, showing all lone pairs. Give approximate values for bond angles a through f, and give the hybridization of all carbon atoms. In acrylonitrile and methyl methacrylate indicate which atoms in each molecule must lie in the same plane. How many s bonds and how many p bonds are there in acrylonitrile and methyl methacrylate?

Short answer

Acrylonitrile–Bond angle,, . The hybridization of the carbon atoms are given below.

C-1 = ${\text{sp}}^{\text{2}}$

C-2 = ${\text{sp}}^{\text{2}}$

C-3 = $\text{sp}$

There are $6\mathrm{\sigma }$ bond and $3\mathrm{\pi }$bonds.

Methyl methacrylate – the values of the bond angle are given below’

$\mathrm{e}\approx {120}^{\circ }$,$d\approx {120}^{\circ }$,$f\approx {109.5}^{\circ }$

C-1 = ${\text{sp}}^3$

C-2= ${\text{sp}}^{\text{2}}$

C-3= ${\text{sp}}^{\text{2}}$

C-4 = ${\text{sp}}^{\text{2}}$

C-5 = ${\text{sp}}^{\text{3}}$

There are$14\mathrm{\sigma }$ bond and $2\mathrm{\pi }$bonds.

Step-by-step solution

Step 1

Acrylonitrile –Thebond angles are $\mathrm{a}\le {120}^{\circ }$,$b\ge {120}^{\circ }$,$c={180}^{\circ }$.

Carbon 1 and carbon 2 are$s{p}^2$hybridized while the carbon 3 is hybridized. All the atoms are in the same plane. There are $6\mathrm{\sigma }$ bond and $3\mathrm{\pi }$bonds. The Lewis structure is given below.

The Lewis structure

Step 2

Methyl methacrylate-Thebond angles are $e\approx {120}^{\circ }$,$d\approx {120}^{\circ }$,$f\approx {109.5}^{\circ }$

Carbon 1 and carbon 5 are$s{p}^2$hybridized while carbon 2, carbon 3, carbon 4 are$s{p}^2$ hybridized. There are $14\sigma$ bond and$2\mathrm{\pi }$ bonds. Carbons 2 , 3 ,4and 5 lie in the same plane. The Lewis structure is given below.

The Lewis structure