Question

Is a molecule of hydrogen chloride $\left( {HCl} \right)$ polar or nonpolar?

Answer 1

The elements having the difference in electronegativities forms a polar covalent bond in which the electrons can be shared between two atoms. But due to the electronegativity difference, one atom gets negative charge and the other atom gets positive charge. Hydrogen chloride has hydrogen and chlorine with differences in electronegativity.

Complete answer:
Hydrogen is an element with atomic number $1$ and has only one electron in its orbital. Chlorine is a non-metal with an atomic number $17$ and has $17$ electrons in its orbitals. Hydrogen can easily lose electrons due to its metallic character and has the value of electronegativity of $2.2$ and chlorine has the value of electronegativity of $3.16$ .
when there is a difference of electronegativity between two elements then those two elements form a polar covalent bond. There is a polarity of electrons from low electronegativity atoms to more electronegativity atoms. Thus, hydrogen gets partial positive charge and chlorine gets partial negative charge. Due to the electronegativity difference hydrogen easily donates its electron to chlorine and can easily lose from hydrogen chloride as ${H^ + }$ . Thus, hydrogen chloride represented by a molecular formula of $HCl$ is a strong acid.
Thus, the molecule of hydrogen chloride $\left( {HCl} \right)$ is polar.

Note:
Polar compounds have dipole moments as there is an unequal distribution of charge. Thus, the atoms can exist as dipoles. Whereas non-polar molecules have opposite bonds with the equal magnitude of charges leads to the cancellation of charges. But Hydrogen chloride has unequal charges and can be known as a polar molecule.