Carbon and it's compounds

synopsis :

Coal, petroleum and its products are compounds of carbon. Carbon is an element and a nonmetal. Since, valency of carbon is equal to four, thus carbon is called tetravalent. Four valency of carbon means, carbon reacts with four atoms of same or different elements to form compounds.

  • In the case of carbon, it has four electrons in its outermost shell and needs to gain or lose four electrons to attain noble gas configuration. If it were to gain or lose electrons –

  1. It could gain four electrons forming C4– anion. But it would be difficult for the nucleus with six protons to hold on to ten electrons, that is, four extra electrons. would require a large amount of energy to remove four electrons leaving behind a carbon cation with six protons in its nucleus holding on to just two electrons.

  • Carbon overcomes this problem by sharing its valence electrons with other atoms of carbon or with atoms of other elements

COVALENT BONDS :

The bonds which are formed by sharing of electrons .

  • For example in hydrogen molecule ,hydrogen has valency 1 and the 2 hydrogen atoms share their electrons to form one sigma bond by using Lewis dot structure

  • The bond between two oxygen molecules is a double bond.

  • The bond between two nitrogen molecules is a triple bond.

  • Likewise in two carbon atoms ,the carbon has valency of 4 which is called as a tetra valency. In order to get noble electronic configuration the 2 carbon atoms share the electrons forming a covalent bond.

Versatile nature of Carbon :

Carbon ,it is a versatile element because it can have a single, double and triple bonds.

It can also form chains, branched chains, and rings when connected to other carbon atoms.

Carbon has many characteristic properties. They are catenation, tetravalency, forming multiple bonds, long chains.

Catenation: The self linkage of carbon atoms is called catenation property.

Isomerism: Compounds which have same molecular formula but different structural formula are called isomers.

The difference in the arrangement of atoms or groups of atoms & is called structural isomerism. There are 4 types of structural isomerism:

  • Chain isomerism

  • Position

  • Functional

  • Metamerism

Tetravalency: Carbon has 4 electrons in its valence shell. therefore it shares its electrons to form covalent bonds with other elements to complete its octet. Due to this tetra valency carbon can form many compounds.

  • SATURATED AND UNSATURATED CARBON COMPOUNDS :

  • Based on the type of chemical bonding between carbon atoms a chemical compound can be either saturated or unsaturated. They can be of Alkanes, Alkenes and Alkynes.

  • A saturated compound is only composed of carbon-carbon single bonds. For example, alkanes are composed of C-C single bonds.

  • Unsaturated compounds can have double bonds and triple bonds both as well. For example, alkenes have double bonds and alkynes have triple bonds.

  • Saturated compounds have only carbon-carbon single bonds whereas unsaturated compounds have carbon-carbon double bonds and triple bonds.

Chains , Branches and Rings :

Carbon atoms form compounds with different type arrangement, such as long chain, branched chain and cyclic chain structures.

Structural Isomers:

STRUCTURAL ISOMERS are defined as hydrocarbons which are having same molecular formula but it has different structural formula.

Example:

Molecular formula of butane is = C4H6

Butane has two types of structural formula.