Hydrogen chloride (HCl) is classified as a molecular compound. This is because it is formed by the sharing of electrons between hydrogen and chlorine atoms, which is characteristic of covalent bonding. In HCl, the hydrogen atom shares its single electron with the chlorine atom, which has seven valence electrons. This sharing allows both atoms to achieve a stable electron configuration.
When HCl is dissolved in water, it forms hydrochloric acid. This means that HCl is an acid. Acids are substances that donate protons (H⁺ ions) when dissolved in water. In the case of HCl, it dissociates completely in water to form H⁺ and Cl⁻ ions, making it a strong acid.
In summary, HCl is a molecular compound and acts as an acid when dissolved in water.