Is HCL a compound, molecule, or both?
The correct answer and explanation is:
Correct Answer: HCl is both a compound and a molecule.
Explanation:
HCl, or hydrogen chloride, is considered both a compound and a molecule because it meets the definitions of both terms in chemistry.
A compound is a substance made up of two or more different elements that are chemically bonded in a fixed ratio. In the case of HCl, it contains two different elements: hydrogen (H) and chlorine (Cl). These two elements are chemically combined in a one-to-one ratio, which qualifies HCl as a compound.
A molecule is a group of two or more atoms that are covalently bonded together. In HCl, the hydrogen and chlorine atoms share electrons to form a covalent bond. This shared electron pair creates a single molecule of hydrogen chloride. Because the atoms are bonded covalently rather than ionically, HCl is also classified as a molecule.
Additionally, HCl is considered a diatomic molecule, meaning it consists of only two atoms. Diatomic molecules can be made of either the same element (like O₂) or different elements (like HCl). Because HCl has two different atoms, it is specifically a heteronuclear diatomic molecule.
When HCl is in its pure gaseous form, it exists as individual molecules. In this state, it behaves as a molecular compound. However, when HCl is dissolved in water, it ionizes to form hydrogen ions (H⁺) and chloride ions (Cl⁻), and it is then referred to as hydrochloric acid. Despite this change in behavior, the original molecular structure of HCl still classifies it as both a compound and a molecule.
Therefore, due to its composition and bonding, HCl fits the criteria of both a compound and a molecule.