1. CARBON AND ITS COMPOUNDS

2. CARBON Carbon belongs to the group IV of the periodic table.
It has four electrons in its outermost orbit, so its valency is four.
Carbon is a non-metal.

3. Compounds of Carbon are Widely Distributed in Nature
The number of carbon compounds is larger than that of all other elements put together.

4. Why so many Carbon Compounds in nature?
Because carbon is chemically unique.
Only carbon atoms have the ability to combine with themselves to form long chains

5. Carbon- Long Chains
A long chain, in turn, provides a convenient backbone of atoms to which other atoms can attach themselves in a variety of ways

6. Allotropes of Carbon In nature, pure carbon occur in two forms-
Diamond
Graphite

7. What are Allotropes ?
Allotropes are elements which are chemically identical, but they differ markedly in their physical properties.
Diamond and Graphite – two allotropes of carbon differ in their physical properties.

8. Physical Properties of Diamond and Graphite
Property
Diamond
Graphite
Appearance
Transparent
Black, Shiny
Hardness
Very Hard
Soft, slippery to touch
Thermal Conductivity
Very poor
moderate
Electrical Conductivity
Poor
Good conductor
Density(kg/m3)
3510
2250
Uses
Jewellery, drilling
Dry cell, electric arc, lubricant, pencil lead

9. How Diamond and Graphite are chemically identical?
These results of thes experiments answer this question:
On heating diamond or graphite in the air, they burn completely to form carbon dioxide.
Equal quantities of diamond and graphite when burned, produce exactly the same amount of carbon dioxide.

10. Why the physical properties of diamond and graphite are so different?
Due to the difference in the arrangement of carbon atoms in diamond and graphite

11. Hydrocarbons Hydrocarbons are compounds of carbon and hydrogen.
The natural source of
hydrocarbons is
petroleum (crude oil)

12. The Simplest Hydrocarbon
A molecule of methane has four hydrogen atoms linked to one central atom of carbon.
Methane CH4

13. Hydrocarbons
Saturated
Alkanes

14. Alkanes
The hydrocarbons methane, ethane propane and butane form a series of carbon compounds known as alkanes
The alkane series can be represented by the general formula

15. Isomerism
Compounds having the same molecular formulae but different structural arrangement of atoms in them are known as isomers, and the phenomenon is known as isomerism
Isomers of Butane – Obtained by rearranging the carbon and the hydrogen atoms

16. Unsaturated Hydrocarbons
Unsaturated hydrocarbons contain a double or triple bond between two carbon atoms.
The one with double bond are called alkenes

17. Alkenes

18. Alkynes
Unsaturated hydrocarbons which contain triple bond between two carbon atoms.