Question

How do I explain the chemical bonding of Hydrogen Fluoride ($$HF$$)?

Answer 1

Hint: Chemical bonding is a type of attraction force which is present between the atoms or ions in a molecule. The presence of such forces gives rise to formation of chemical bonds which are found to be either ionic or covalent in nature.

Complete step by step answer:
The chemical bond present between the atoms or ions is primarily characterized by two types. One is formed of ionic bond and the other is formed of covalent bond. The ionic bond is produced by donation of electrons from one species to another species. The covalent bond is produced by the sharing of electrons between the bonded species.
The electron density in ionic bonds lies on the atoms which are more electronegative and in covalent bonds the electron density lies in between the two bonded atoms. The bonded atoms in ionic bonds have electronegativity differences but covalent bonds have similar electronegativity.
The compound given in this question is hydrogen fluoride. Hydrogen fluoride is composed of a single bond between one hydrogen atom and one fluorine atom. The hydrogen atom has only one electron in the outermost or valence shell for forming bonds. The fluorine atom has $$7$$ electrons in the outermost or valence shell for forming bonds.
Thus hydrogen is electropositive and fluorine is highly electronegative. But the bond between HF is not ionic in nature but rather it is covalent. The huge electronegativity difference between the bonded atoms in $$H-F$$ allows the molecule to form intermolecular hydrogen bonds. Thus the molecule exists as
$$\cdot \cdot \cdot \cdot \cdot H-F\cdot \cdot \cdot \cdot \cdot H-F\cdot \cdot \cdot \cdot \cdot H-F\cdot \cdot \cdot \cdot \cdot$$
The bond between $$H-F$$ is sometimes considered as ionic. It is because when hydrofluoric acid is treated with water it dissociates completely in water. The $$H-F$$ is highly acidic as it readily liberates $$H^{+}$$ ions.

Note:
The bond in $$H-F$$ is referred to as a polar covalent bond which also possesses ionic character. The molecule is stable due to presence of intermolecular hydrogen bonding because of large electronegativity difference between the bonded atoms.