Q10.34P - 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) ${\mathbf{O}}_3$ (b) ${\mathbf{H}}_3{\mathbf{O}}^{+}$ (c)  ${\mathbf{NF}}_3$

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: O 3

The shape of the molecule is Pyramidal. The Oxygen atom is sp² hybridized with an expected bond angle of ${\mathbf{120}}^0$. The single lone pair on oxygen reduces the bond angle from the expected value.

Step 2: H 3 O +

The shape of the molecule is Pyramidal. The Oxygen atom is sp³ hybridized with an expected bond angle of $\mathbf{109}\mathbf{.}{\mathbf{5}}^0$ . There is only one lone pair on Oxygen which reduces the bond angle from the expected value to a lesser extent. 

Step 3: NF 3

The shape of the molecule is Pyramidal. The nitrogen atom is sp³ hybridized with expected bond angle of $\mathbf{109}\mathbf{.}{\mathbf{5}}^0$. However, the lone pair on nitrogen reduces the bond angle from the expected value.