Typical Hydrogen Bonded Compounds

A few examples of compounds which exhibit hydrogen bonding are discussed below :

Hydrogen Fluoride (HF)

In the solid state, hydrogen fluoride consists of long zig-zag chains of molecules associated together through hydrogen bonds. Hydrogen fluoride molecule is represented as (HF)_n. With fluorine, the hydrogen bond is so strong that HF molecules remain associated through

H-bonding even through the gaseous state. In the liquid or gaseous state, the chain however, becomes linear.

Water(H

₂O)

Water is a typical polar compound, which exhibits Hydrogen bonding. In addition to two (O-H) bonds in water, oxygen atoms form two hydrogen bonds. Consequently, four hydrogen atoms, two by covalent bonds and two by hydrogen bonds tetrahedrally surround each oxygen atom. The associated water molecules may be expressed as (H₂O)_n. It is due to hydrogen bonding that water exists in its associated form.Also, ice has has a cage like structure due to hydrogen bonding.

Ammonia (NH

₃)

Ammonia molecule has an electronegative nitrogen atom bonded to three hydrogen atoms. Differences in electronegativity between nitrogen and hydrogen makes each hydrogen atom acquires positive charge. Thus, in the molecule, there is one negative site and three positive sites so that the molecules of ammonia associate through hydrogen bonding to form long chains.