Question

Do we consider that the intramolecular bond of HCl changes from covalent to ionic when it's dissolved in water?

Explanation: Highly polar water molecules polarize HCl and affect its electronegativity difference. Is that true?

Answer 1

No, we consider that the polar covalent bond breaks heterolytically

Explanation:

Because Cl is more electronegative than H, the gaseous molecule HCl contains a polar covalent bond in which the chlorine atom has a greater attraction towards the bonding pair of electrons.

When HCl is dissolved in water, the H and Cl atoms are surrounded by water molecules and become solvated. The hydrogen atom accepts a lone pair from a water molecule and becomes `H_3O^+` and as a result the bond between H and Cl breaks with both electrons in the bonding pair going to the Cl atom, making it a `Cl^-` ion. So, in summary there isn't an ionic bond between H and Cl in water. The two atoms have become ions but are separate individual ions in the solution.