Question

What is the reason for the formation of polar covalent bond in HCl?

• A. It reacts with water.
• B. The difference in the atomic mass of H and Cl.
• C. Chlorine is more electronegative than hydrogen.
• D. Hydrogen is more electronegative than Chlorine.

Answer 1

The correct option is C

Chlorine is more electronegative than hydrogen.

The force with which an atom attracts a bonding pair of electrons towards itself is called electronegativity. In the case of HCl, the two nuclei have different attractive forces(electronegativities), thus, they “pull” the electron pair to different degrees. Chlorine is more electronegative than hydrogen, as a result, the electron pair is shifted more towards the chlorine atom.

That is, the electron pair that is bonding HCl together shifts toward the chlorine atom because it has a larger electronegativity value. A bond in which the electron pair is shifted toward one atom is called a polar covalent bond.