Carbon & Its Compound

Carbon & Its Compound

Carbon is non-metal having atomic number 6 and mass number 12. It is placed in group (IV) A or group 14 in periodic table.

Carbon is the sixth most abundant element in the universe. It can exist in the free state or in the form of its compounds. It is the major chemical constituent of most organic matter. Carbon is the second most common element in the human body after oxygen. Carbon is present in coal, oil, and natural gas.

Carbon atoms can form compounds by combining with other carbon atoms as well as atoms of other elements. Carbon has the unique property of forming long chains of carbon atoms. These long chains serve as a backbone on which various groups can attach to give a large variety of compounds.

Carbon can form bonds with atoms of other elements such as hydrogen (H), nitrogen (N), oxygen (O), sulphur (S), and halogens. It also has the property of self combination, i.e., bond formation with the other carbon atoms. Thus carbon can form long chains of carbon atoms. This unique property of forming long chains is known as catenation.

Compounds of Carbon

The compounds of carbon can be classified as organic and inorganic compounds. Earlier the organic compounds were defined as those compounds which originated from living organisms, but it is now possible to synthesize organic compounds in the laboratory; therefore, they are now defined as compounds of carbon. The compounds of carbon, which are not organic compounds, are called inorganic compounds.

Organic Substances

The chemical substances found in living beings were called organic substances in earlier time. But at present, the modified concept about the organic chemistry which are internationally accepted by IUPAC on the basis of consensus is given as below:

1. Organic Compounds

Organic compounds are broadly classified into two categories :
I. Aliphatic or Open Chain Compounds
II. Carbocyclic or Homocyclic Compounds

I. Aliphatic or Open Chain Compounds
Organic compounds in which carbon atoms are attached in open chain are called aliphatic compounds. These compounds exist in such a way that carbon atoms are attached in branched or straight chains.

II. Carbocyclic or Homocyclic Compounds
Those cyclic compounds which are composed from carbon atoms only are called carbocyclic or Homocyclic compounds.

These carbon cyclic compounds may further be divided into two groups:
(i) Aromatic Compounds : The word Aromatic is made from word Aroma which implies smell. The cyclic carbon compounds in which six carbon atoms form a closed chain are called aromatic compounds. The organic compounds like benzene, phenol, aniline, etc. are examples of aromatic compounds.

(ii) Alicyclic Compounds : Some characteristics of cyclic compounds which have closed chains exhibit more resemblance to the aliphatic.

2. Heterocyclic Compounds

The cyclic compounds in which closed chain is made from the elements other than carbon are called heterocyclic compounds.
Methane is called the father of all the aliphatic organic compounds. Benzene is called the father of all the aromatic organic compounds.