What is Organic Chemistry ?
Organic chemistry is the branch of Chemistry that deals with the study of structure, composition, chemical reactions, and other physical and chemical properties of hydrocarbons and their derivatives.
What are hydrocarbons and their derivatives?
Hydrocarbons are the compounds of purely carbon and hydrogen e.g alkanes, alkenes, alkynes and aromatic compounds like benzene, napthalene, anthracene and many others. Not the atom of any other element is present in them. If any other atom is attached with these hydrocarbons, then these compounds are called as the derivatives of hydrocarbons. They may contain elements like Oxygen, Nitrogen, Halogens, Sulphur, Phosphorus, and some metals like magnesium, potassium, copper,iron etc. For example alcohols(R-OH), Amines (R-NH2), Alkyl halides (R-X), Carboxylic acids(R-COOH), Phenols, substituted aryls, Nitro benzene, Grignard reagents(R-Mg-X)and many others. These compounds are called as derivatives because they are formed by the substitution of a group in a hydrocarbons.
What are the classes of organic compounds?
Organic compounds are divided into different classes on the basis of the functional group attached to the hydrocarbons. There are too many classes of organic compounds, a few of them are listed below.
Some common classes of organic compounds with general structures and class name.
How do we study organic compounds?
About 900 million organic compounds exists in the today's world and they are increasing exponentially. These compounds may be naturally occurring or synthesized artificially in the laboratory for commercial purposes. As, it would be quite impossible to study these organic compounds individually. So, to simplify the study of organic compounds, these are classified or divided into homologous series.
What are homologous series?
Homologous series is a series of organic compounds having same general formula (the length of carbon chain increases but have the same functional group), chemical properties , show similar chemical reactions and have comparable methods of preparation. The successive members of the homologous series vary from each other by a CH2 group. The members of homologous series differ from each other because of their chain length.
For example, the hydrocarbons having OH- group attached to the carbon atom, form a homologous series of compounds called as Alkanols (alcohols). The chemical formula and chain length of the adjacent members of this series differ from each other by -CH2 (methyl group).


