Q10.99 CP - Chemistry: Molecular Nature Of Matter And Change

Question

Phosphorus pentachloride, a key industrial compound with annual world production of about $\mathbf{2}\mathbf{\times }{\mathbf{10}}^{\mathbf{7}}\mathbf{kg}$ , is used to make other compounds. It reacts with sulfur dioxide to produce phosphorus oxychloride ( ${\mathbf{POCl}}_{\mathbf{3}}$) and thionyl chloride  $\left({\mathbf{SOCl}}_{\mathbf{2}}\right)$. Draw a Lewis structure, and name the molecular shape of each product

Step-by-Step Solution

Answer

• Phosphorus oxychloride has tetrahedral geometry.
• The shape of thionyl chloride is trigonal pyramidal with tetrahedral geometry.

Step 1: Phosphorus oxychloride

Phosphorus oxychloride has a tetrahedral molecular geometry as the central phosphorus atom is forming 4 bonds with atoms. The hybridization is ${\text{sp}}^{\text{3}}$. The shape of phosphorus oxychloride is not distorted because all the four atoms are arranged in symmetry around the P atom.

Step 2: Thionyl chloride

The molecular shape of thionyl chloride is trigonal pyramidal and its electronic geometry is tetrahedral. Lewis dot structure of thionyl chloride contains two single bonds, one double bond, and one lone pair of electrons on S-atom.

Hybridization of thionyl chloride is  ${\text{sp}}^{\text{3}}$. Because of the presence of lone pair of electrons on S-atom, its geometry is distorted and it becomes trigonal pyramidal.