Organic Chemistry

Introduction

A wide range of compounds existing either naturally or synthetically prepared are known to possess the element carbon. This forms a branch of chemistry, known as Organic Chemistry. Over three million different organic compounds have been characterized & every year tens of thousands of new substances are added to the list.

Antoine Lavoisier

In 1774, Antoine Lavoisier showed that compounds obtained from vegetable and animal sources always contained at least carbon and hydrogen.

Carbon is not the only element found in organic compounds. Hydrogen atoms are almost always present. In addition organic compounds often contain atoms of oxygen, nitrogen, phosphorus, sulfur or the halogens. The bonds formed by carbon with other carbon atoms or other atoms can be single, double or triple bonds.

Standard conventions used to represent these bonds are as follows:

 

No. of lines	Type of bond	Example
Single	Single	C - C, C - H
Double	double	C = C, C = O
Triple	triple	C � C, C � N

Organic compounds differ considerably from inorganic compounds. The following comparison illustrates the difference between organic and inorganic compounds. Remember that there are exceptions to every point of comparison

	Organic compounds	Inorganic compounds
(i)	Relatively few elements (mainly C, H, O, N, S, P, F, Cl, Br, I) are involved.	All elements are involved.
(ii)	Bonds are covalent.	Bonds are ionic or electrovalent.
(iii)	Sparingly soluble or insoluble in water but soluble in non-aqueous solvents (organic solvents).	Soluble in water but insoluble in organic solvents.
(iv)	Volatile in nature.	Non-volatile in nature.
(v)	Non electrolytes	Electrolytes
(vi)	Rate of reaction is slow and a catalyst is needed.	Rate of reaction is fast and a catalyst is not needed.
(vii)	Mostly inflammable	Not inflammable
(viii)	Complex structure	Simple structure
(ix)	Isomerism is very common.	Isomerism is not very common.