Question

why H-bonding does not exist in HCL , though chlorine is electronegative?

Answer 1

Hydrogen bonds are attractions between a δ⁺ hydrogen on one molecule and a lone pair on a very
electronegative atom (N, O or F) on another molecule. Although Cl is electronegative atom but its electronegativity is less than N, O and F due to its bigger size.
Due to its less electronegativity, Hydrogen does not have that much positive charge, hence this is not attracted to lone pair of Cl atom of another molecule. Therefore H- bonding is not that significant in HCl.