Question

Determine the electron-group arrangement, molecular shape, and ideal bond angle(s) for each of the following: (a) ${\mathbf{SO}}_3$ (b)${\mathbf{N}}_2\mathbf{O}$ (N is central) (c)${\mathbf{CH}}_2{\mathbf{Cl}}_2$ .

Short answer

The shapes and bond angles of molecules can be determined from the VSEPR theory. The deviations arise mainly due to lone pair-lone pair repulsions.

Step-by-step solution

Step 1:  SO3

The sulphur atom ${\mathbf{sp}}^2$ is hybridised. The structure of the molecule would be trigonal planar around the central atom sulphur. The ideal bond angle would bedata-custom-editor="chemistry" ${\mathbf{120}}^0$ .

Step 2:  N2O

The expected arrangement would be linear around the central atom N. Ideal bond angle would be${\mathbf{180}}^0$.

Step 3:  CH2Cl2

The expected shape of the molecule is tetrahedral. The expected bond angle is $\mathbf{109}.{\mathbf{5}}^0$ . However, the bond pair of C-Cl bond and C-H bond experience repulsion which may decrease the bond angle between C-H bond and increase between C-Cl.