Question

What kind of a molecule is ${\mathrm{PCl}}_3$?

• A. Non-polar covalent
• B. Ionic
• C. Polar covalent
• D. None of these

Answer 1

The correct option is C

Polar covalent

Explanation for the correct option:

(C) Polar covalent

• ${\mathrm{PCl}}_3$ is polar because Chlorine ($\mathrm{Cl}$) is more electronegative than Phosphorus ($\mathrm{P}$).
• Therefore, the shared electron pair is shifted towards the Chlorine atoms and the molecule is polar.
• It is covalent because three our of total valence electrons of the Phosphorus atom are shared with the three Chlorine atoms to complete the octet and form polar covalent bonds.

Explanation for the incorrect options:

(A) Non-polar covalent

• Since Chlorine ($\mathrm{Cl}$) is more electronegative than Phosphorus ($\mathrm{P}$), the molecule cannot be non-polar.

(B) Ionic

• Since sharing of electrons takes place between Phosphorus and Chlorine atoms, therefore, it cannot be an ionic molecule.

Hence, option (C) is correct. ${\mathrm{PCl}}_3$ is polar covalent.