Class 10th Chapter - Carbon and Its Compounds
· Instead of gaining and loosing electrons, carbon shares its 4-electrons with another element or carbon to form molecule.
· Covalent bonds are formed as a result of sharing of electrons. Example- H2, O2, N2. Covalent compounds have low melting point and boiling point due to small intermolecular forces.
· H2 forms by sharing valence electrons (1 per atom of H) and produce single bond between two hydrogen atoms.
· O2 forms by sharing valence electrons (2 per atom of O) and produce double bond between two oxygen atoms.
· N2 forms by sharing valence electrons (3 per atom of N) and produce triple bond between two nitrogen atoms.
· Methane, CH4 is simple carbon compounds and used as a fuel on large scale and also a major component of CNG (Compressed Natural Gas). Methane formed due to sharing of 4 valence electrons of carbon with 4 hydrogen atoms.
Allotropes of Carbon
Carbon have three allotropes i.e. Diamond, Graphite and fullerene.
Diamond formed due to rigid three dimensional structures of carbon atoms because each carbon atom bonded to another 4 carbon atoms. It is hardest substance.
Graphite formed due to presence of hexagonal array layers above one another, and layers of hexagonal arrays formed because each carbon atom bonded to another 3 carbon atoms with 2 single and 1 double bond. It is smooth, slippery and very good conductor of electricity.
Fullerenes (C-60) are also an allotrope of carbon in which carbon atoms are arranged in football like shape.
Versatile Nature of Carbon
Carbon shows versatile nature because it has two characteristics features which are catenation and tetravalency. These both feature gives large numbers of compounds.
Catenation is the property of carbon atom to form bond with other carbon atom to produce large molecule. Catenation produces large long chains, branched chains and ring structures.
Compounds with single bonds are known as saturated compounds while compounds with double or triple bonds are known as unsaturated compounds.
Property of carbon atom to form 4 bonds with other atom of carbon or other element is known as tetravalency, as carbon have four valence electrons.
Saturated and Unsaturated Carbon Compounds
1. Saturated Carbon Compounds:-
Carbon compounds containing single bond is called saturated Carbon Compounds.
Example- Ethane, C2H6
2. Unsaturated Carbon Compounds:-
Carbon compounds containing double or triple bond is called unsaturated Carbon Compounds.
Example- Ethene, C2H4
Chains, Branches and Rings
Carbon is the element which forms chains, branches and rings in its structures.
Carbons have property to form chains, when one carbon atom attach to another carbon atom like chains.
Example- Ethane(C2H6), Propane(C3H8), Butane(C4H10), Pentane(C5H12), Hexane(C6H14).
Carbon forms branches when one and two carbon attach to carbon chain.
Carbon forms rings when all carbon atoms attach to one another means first carbon chain atom attach to last carbon chain atom giving ring structure.
Alkane, Alkene and Alkynes
As we know hydrocarbons are the carbon compounds containing carbon and hydrogen.
Saturated hydrocarbons containing single bonds are known as alkanes.
Example- Ethane (C2H6)
Unsaturated hydrocarbons containing double bonds are known as alkenes.
Example- Ethene (C2H4)
Unsaturated hydrocarbons containing triple bonds are known as alkynes.