Chemistry 2004 JAMB Past Questions - Question 11: The property of chlorine which causes hydrogen chloride to be more ionic than the chlorine molecule is its

Correct Answer

D

Explanation

 The property of chlorine that leads to hydrogen chloride being more ionic than the chlorine molecule is electronegativity. Electronegativity is the tendency of an atom to attract electrons in a chemical bond. Chlorine is more electronegative than hydrogen, meaning it has a higher affinity for electrons.

In a chlorine molecule (Cl₂), the two chlorine atoms share electrons in a covalent bond. However, when chlorine reacts with hydrogen to form hydrogen chloride (HCl), the electronegativity difference between chlorine and hydrogen is significant. Chlorine attracts the shared electrons more strongly, resulting in a polar covalent bond.

The electronegativity difference in the H-Cl bond is large enough that the electron pair is pulled closer to the chlorine atom, giving it a partial negative charge, while the hydrogen atom acquires a partial positive charge. This charge separation creates an ionic character in the H-Cl bond, making hydrogen chloride more ionic compared to the nonpolar covalent chlorine molecule (Cl₂).