Question

Why is ${\mathrm{CCl}}_4$ more covalent than $\mathrm{LiCl}$ ?

Answer 1

1. Lithium and carbon belong to the same period.
2. Along a period, the size of atoms decreases hence, carbon will be the smallest in size and lithium will be the largest.

Fajan’s rule of polarization:

1. The high charge and small size of the cation higher will be the polarizability.
2. The high charge and large size of the anion higher will be the polarizability.

The covalent character of ${\mathrm{CCl}}_4$ and $\mathrm{LiCl}$:

• In the carbon tetrachloride(${\mathrm{CCl}}_4$) and Lithium chloride($\mathrm{LiCl}$), the anion is the same chloride.
• So, the covalent character of the compound depends upon the cation.
• Carbon has the smallest size as compared to Lithium. So, the polarizing power of carbon is high.
• Due to the high polarizing power of Carbon, ${\mathrm{CCl}}_4$​ will have maximum covalent character.