INTRODUCTION

Aliphatic and Aromatic Hydrocarbons

• Hydrocarbons are the simplest class of organic compounds and are composed of hydrogen and carbon. This class can be further divided into two groups: aliphatic hydrocarbons and aromatic hydrocarbons.

• Alkanes is known as saturated hydrocarbons, are compounds that consist entirely of single bonds, so that each carbon atom is connected to four other atoms.

• Alkenes is known as unsaturated hydrocarbons because some of the carbons are connected to fewer than four neighboring atoms. Alkenes contain at least one double bond.

• Aromatic hydrocarbons, or arenes, which contain a benzene ring, were originally named for their pleasant odors. A benzene ring is a ring of six carbons with alternating double and single bonds.

• Alkanes undergoes only free radical substitution reaction with halogen in the presence of sunlight.

• Alkenes undergoes addition reaction with halogen in the presence of sunlight and in the dark.

• Arenes undergoes eletrophilic substitution reaction and toluene (methylbenzene) undergoes free radical substitution reaction with halogen in the presence of sunlight.

• Alkanes can not be oxidized by cold alkaline solution of potassium permanganate (Baeyer’s Test).

• Alkenes can be oxidized by cold alkaline solution of potassium permanganate (Baeyer’s Test) to form diol.

We define organic Chemistry

as the Chemistry of carbon compounds.

-August Kekule