Q10.37P - Chemistry: Molecular Nature Of Matter And Change

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)  ${\mathbf{CH}}_2{\mathbf{Cl}}_2$ .

Step-by-Step Solution

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 1: SO 3

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 be  data-custom-editor="chemistry" ${\mathbf{120}}^0$ .

Step 2: N 2 O

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

Step 3: CH 2 Cl 2

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.