Q10.47P - Chemistry: Molecular Nature Of Matter And Change

Question

Arrange the following ACl_n species in order of decreasing Cl-A-Cl bond angles:  ${\mathbf{SCl}}_2$ , data-custom-editor="chemistry" ${\mathbf{OCl}}_2$ ,  ${\mathbf{PCl}}_3$ , ${\mathbf{SiCl}}_4$  , data-custom-editor="chemistry" ${{\mathbf{SiCl}}_6}^{2-}$  

Step-by-Step Solution

Answer

The order of decreasing bond angles is: ${\mathbf{PCl}}_3$  > ${\mathbf{OCl}}_2$  > ${\mathbf{SCl}}_2$  > ${\mathbf{SiCl}}_4$ >  ${{\mathbf{SiCl}}_6}^{2-}$  .

Step 1: SCl 2

The shape of the molecule has a bond angle  $\mathbf{120}\mathbf{°}$. The lone lone pair repulsion is greater and the angle decreases to a greater extent than in OCl_2.

Step 2: OCl 2

The shape of the molecule is bent with expected bond angle of $\mathbf{120}\mathbf{°}$  . The lone pair repulsion is lesser and the angle decreases to a lesser extent than in SCl_2.

Step 3: PCl 3

The shape of the molecule is trigonal planar. The bond angle is $\mathbf{120}\mathbf{°}$ . There are no deviations present.

Step 4: SiCl 4

Tetrahedral’s shape with a bond angle of  $\mathbf{109}\mathbf{.}{\mathbf{5}}^o$ . No deviations in bond angle.

Step 5: SiCl 6 2 -

The shape is octahedral with a bond angle of  $\mathbf{90}\mathbf{°}$.