Both sodium and hydrogen are electropositive elements. Sodium reacts with chlorine to form an electrovalent compound but hydrogen reacts with chlorine to form a covalent compound-explain.

Explanation

The ionisation enthalpy of smaller H-atom is sufficiently higher than that of larger Na-atom. Because of lower ionisation enthalpy, sodium reacts with chlorine through the formation of `Na^(+)` ion to form the electrovalent compound, NaCl. On the other hand, because of much higher ionisation enthalpy, hydrogen does not react with chlorine through the formation of `H^(+)`. instead both H and `Cl`- atoms donate one electron each to form an electron pair and produce the covalent compound. HCl by sharing the electron pair equally.