0Organic Compounds
Initially, compounds of carbon could only be obtained from living sources and there was no way of synthesizing them. Hence, carbon compounds are also known as organic compounds. Carbon forms a large number of compounds. So far, formulae of about 3 million carbon compounds are known.
Cause of formation of such a large number of compounds by carbon:
- Carbon can form bonds with other carbon atoms. This property of carbon is known as CATENATION. Because of catenation, carbon can form a long chain; while making bond with other carbon atoms. Carbon can make single, double and triple bonds by catenation.
- Carbon can form bonds with other carbon atoms. This property of carbon is known as CATENATION. Because of catenation, carbon can form a long chain; while making bond with other carbon atoms. Carbon can make single, double and triple bonds by catenation.
- Carbon can form branched chain; along with straight chain; while combining with carbon atoms, i.e. because of the property of catenation.
Example:
Carbon can also form bonds with other types of monovalent atoms; apart from carbon. Carbon can make long chain combining with other atoms also. For example; carbon can form bonds with oxygen, hydrogen, nitrogen, etc.
Carbon-carbon bonds are very stable, which makes the compounds of carbon stable.
Hydrocarbon:
(Hydrogen + Carbon = Hydrocarbon) Compounds formed because of the combination of hydrogen and carbon are known as hydrocarbons. There are two types of hydrocarbon, viz. saturated hydrocarbon and unsaturated hydrocarbon.
Saturated hydrocarbons: Hydrocarbons having single bonds are known as SATURATED HYDROCARBONS. Saturated hydrocarbons are known as ALKANE. These are also known as paraffin. Example: Methane, Ethane, Propane, etc.
Unsaturated hydrocarbon: Unsaturated hydrocarbons are of two types – Hydrocarbon with double bond and hydrocarbon with triple bond.
Hydrocarbon with double bond: Hydrocarbons having at least one double bond are known as ALKENE. Example: Ethylene, Propylene, Butylene, etc.
Hydrocarbon with triple bond: Hydrocarbons having at least one triple bond are known as ALKYNE. Example: Ethyne, Propyne, Butyne, etc.
Alkane
ALKANE: Hydrocarbons having only single bonds are known as alkane. These are saturated hydrocarbons. Alkane are also known as paraffin. The general formula of alkane is CnH2n+2
If C = 1, then; CnH2n+2 = C1H2x1+2 = CH4
Name of this compound is methane. It can be shown by following structural formula:
If C = 2, then; CnH2n+2 = C2H2x2+2 = C2H6
Name of this compound is ethane. It can be shown by following structural formula:
Structural formula of ethane can also be written as CH3CH3 or CH3 − CH3
If C = 3, then; CnH2n+2 = C3H2x3+2 = C3H8
Name of this compound is propane. It can be shown by following structural formula:
Structural formula of propane can also be written as CH3CH2CH3 or CH3 − CH2 − CH3
If C = 4, then; CnH2n+2 = C4H2x4+2 = C4H10
Name of this compound is butane. It can be shown by following structural formula:
Structural formula of propane can also be written as CH3CH2CH2CH3 or CH3 − CH2 − CH2 − CH3
If C = 5, then; CnH2n+2 = C5H2x5+2 = C5H12
Name of this compound is pentane. It can be shown by following structural formula:
Structural formula of pentane can also be written as CH3CH2CH2CH2CH3 or CH3 − CH2 − CH2− CH2 − CH3
If C = 6, then; CnH2n+2 = C6H2x6+2 = C6H14
Name of this compound is hexane. It can be shown by following structural formula:
Structural formula of hexane can also be written as CH3CH2CH2CH2CH2CH3 or CH3 − CH2 − CH2 − CH2 − CH2 − CH3
If C = 7, then; CnH2n+2 = C7H2x7+2 = C7H16
Name of this compound is heptane. It can be shown by following structural formula:
Structural formula of heptane can also be written as CH3CH2CH2CH2CH2CH2CH3 or CH3 − CH2 − CH2 − CH2 − CH2 − CH2 − CH3
If C = 8, then; CnH2n+2 = C8H2x8+2 = C8H18
Name of this compound is octane. It can be shown by following structural formula:
Structural formula of octane can also be written as CH3CH2CH2CH2CH2CH2CH2CH3 or CH3 − CH2 − CH2 − CH2 − CH2 − CH2 − CH2 − CH3
If C = 9, then; CnH2n+2 = C9H2x9+2 = C9H20
Name of this compound is nonane. It can be shown by following structural formula:
Structural formula of nonane can also be written as CH3CH2CH2CH2CH2CH2CH2CH2CH3 or CH3 − CH2 − CH2 − CH2 − CH2 − CH2 − CH2 − CH2 − CH3
If C = 10, then; CnH2n+2 = C10H2x10+2 = C10H22
Name of this compound is decane. It can be shown by following structural formula:
Structural formula of decane can also be written as CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3or CH3 − CH2 − CH2 − CH2 − CH2 − CH2 − CH2 − CH2 − CH2 − CH3
| Saturated Hydrocarbons (Alkane) | ||
|---|---|---|
| Name | No. of carbon atoms | Formula |
| Methane | 1 | CH4 |
| Ethane | 2 | C2H6 |
| Propane | 3 | C3H8 |
| Butane | 4 | C4H10 |
| Pentane | 5 | C5H12 |
| Hexane | 6 | C6H14 |
| Heptane | 7 | C7H16 |
| Octane | 8 | C8H18 |
| Nonane | 9 | C9H20 |
| Decane | 10 | C10H22 |
Unsaturated Hydrocarbons
Alkene: Hydrocarbons having at least one double bond between two carbon atoms are known as ALKENE. General formula of alkene is CnH2n; where n is number of carbon atoms.
If C = 1 then CnH2n = C1H2x1 = CH2
Name of this compound: Since, hydrocarbon having one carbon atom is known as Methane. Thus, Methane – ane + ene = Methene. But, alkene does not exist with one carbon atom, thus, methene does not exist.
If C = 2 then CnH2n = C2H2x2 = C2H4
Name of this compound is: ethane − ane + ene = ethene. This molecule can be shown by following structural formula.
If C = 3 then CnH2n = C3H2x3 = C3H6
Name of this compound is: butane − ane + ene = butene. This molecule can be shown by following structural formula.
Other alkenes are formed in similar way.
Alkyne
Hydrocarbons having at least one triple bond between two carbon atoms are known as alkyne. (Alkane – ane + yne = Alkyne). Similarly;
Ethane – ane + yne = Ethyne
Propane – ane + yne = Propyne
Butane – ane + yne = Butyne
Pentane – ane + yne = Pentyne
General formula of alkyne is CnH2n − 2. As in case of alkene, minimum two carbon atoms are required to form alkyne.
If C = 2, then; CnH2n − 2 = C2H2x2 − 2 = C2H2
The name of this compound is ethyne. This can be shown by following structural formula.
If C = 3, then; CnH2n − 2 = C3H2x3 − 2 = C3H4
The name of this compound is propyne. This can be shown by following structural formula.
If C = 4, then; CnH2n − 2 = C4H2x4 − 2 = C4H6
The name of this compound is butyne. This can be shown by following structural formula.
Other alkynes are formed in similar way.
Cyclic Hydrocarbon:
Carbon can form cyclic structure combining with carbon atoms. Such hydrocarbons are known as cyclic hydrocarbon. Structural formulae of some of the cyclic hydrocarbons are as follows:
