Chapter 21.5, Problem 34SSC

Interpretation Introduction

Interpretation:

The differences between aromatic and aliphatic hydrocarbons are to be written.

Concept introduction:

The compounds which are cyclic, unsaturated and follow the n-Huckel rule are known as aromatic compounds and the straight chain hydrocarbons are called aliphatic hydrocarbons.

Answer to Problem 34SSC

In aromatic hydrocarbons the linking of carbon compounds is done in a structure which is ring shaped and contains pi-electrons which are delocalized in accordance to n-Huckel rules. They have a characteristic pleasant odor.

On the other hand, in aliphatic compounds the linking of carbon compounds takes place among straight chained or cyclic manner and they may or may not have pi electrons but there is no delocalization of electrons and they have pungent odor when compared to aromatic hydrocarbons.

Explanation of Solution

The difference of properties of the aliphatic and aromatic hydrocarbons exists due to the chain of delocalized pi electrons which create a resonance effect which in turn, creates a new set of chemical properties for the aromatic hydrocarbons which are different from the aliphatic hydrocarbons.