Answer – HCl (hydrogen chloride) is a polar covalent compound.

Explanation:

When atoms combine to form molecules, the bonds between them may be of two kinds – ionic or covalent. Ionic bonds are formed when one atom gives up electrons and acquires a positive charge (becoming a cation), while the other atom picks up those electrons and becomes negatively charged (becoming an anion). 

In covalent bonds, on the other hand, pairs of electrons (one from each atom’s valence shell) are shared between the atoms, allowing them to fulfill the octet rule. Polarities arise when there is a significant difference between the atoms’ electronegativities. In polar covalent compounds, the electrons are unequally shared; the atom with greater electronegativity exerts a greater pull on the electrons. This causes the atoms to acquire partial charges without losing/gaining electrons and becoming ions.

In hydrogen chloride or HCl, chlorine and hydrogen need only one electron each to fill their valence shells while having notably different electronegativities – chlorine has an electronegativity of 3.16, while that of hydrogen is 2.2. At the same time, the difference is not vast enough for chlorine to exert a strong enough attractive force to detach and acquire hydrogen’s electron. Thus, the two share their valence electrons in a polar covalent bond where chlorine has a partially negative charge and hydrogen has a partially positive one.

The polarity allows HCl to easily dissolve in other polar solvents. When it does so in water, the product is hydrochloric acid.

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