Question

What feature is common to all aromatic hydrocarbons?

Short answer

The common feature to all aromatic hydrocarbons is the presence of a delocalized or 'aromatic' ring structure with alternating single and double bonds.

Step-by-step solution

Definition of Aromatic Hydrocarbons

Aromatic hydrocarbons, also known as arenes or aryl hydrocarbons, are hydrocarbons that contain at least one aromatic ring. An example of an aromatic hydrocarbon is benzene.

Structure of Aromatic Hydrocarbons

Aromatic hydrocarbons always contain a ring of atoms connected through single and double alternating bonds. These are known as conjugated pi bonds, which form a delocalized bonding system. This structure is often represented as a cycle with a ring inside.

Fundamental Feature of Aromatic Hydrocarbons

The key feature that all aromatic hydrocarbons share is the presence of this ring formation or cyclic structure with alternating single and double bonds. These structures typically exhibit special stability as a result of resonance or delocalization of the bonding electrons within the ring.