Organic Chemistry | Organic Compounds | Characteristics Of Organic Compounds

1. Organic Chemistry:

The branch of chemistry which deals with the study of hydrocarbons and their derivafives is called organic chemistry.

2. Organic Compounds:

All the compounds of carbon except oxides of carbon, carbonates, bicarbonates and carbides of metals are called organic compounds. Thus Co, Co2, Na2Co3, NaHCo3 and CaC2 are no more organic compounds, they are inorganic compounds.

2.1. Examples:

Methane (CH4), C2H6 (ethane)

Ethlalcohol (C2H5OH), Sugar (C12,H22,O11)etc.

3. Vital Force Theory:

The term organic is derived from organism because organic materials like sugar starch, cotton, leather, and many more was obtained from living organism and could not prepared in laboratory, it was believed that a mysterious force called vital force is responsible for the formation of organic compounds in nature this theory is called vital force theory.

3.1. Wohler’s Work:

In 1828, a German chemist Wohler synthesized urea in the laboratory from inorganic compound which was previously obtained from animal urine. He Synthesized urea (NH2)2Co from ammonium cynate NH4CNO.

3.2. Chemical Reaction:

NH4CNO ---> NH2 --C-- NH2

The synthesis of urea proved that the in flounce of living organisms is not necessary for the production of organic compounds.

4. Characteristics Of Organic Compounds:

Organic compounds have many common characteristics some of them are as under.

4.1. Covalent Nature:

Organic compounds contain covalent bonds and are mostly non polar in nature.

4.2. Lower Melting Points and Boiling Points:

All the organic compounds have lower melting points and boiling points then inorganic compounds.

4.3. Thermal Instability:

Many organic compounds are thermally unstable they decompose into simpler molecules when heated above 500oC.

4.4. Molecular Mass:

Their molecular masses are very high e.g sugar (sucrose) =342g. etc.

4.5. Inflammability:

Most of the organic compounds are inflammable and burns exothermically in a sufficient supply of air to yield carbon dioxide water and heat energy.

4.6. Burns With Smoky Flame:

Most of the organic materials give smoky flame upon burning.

4.7. Isomerism:

In organic compounds there is a large number of compounds that have some molecular formula but different structural formula, this phenomena is known as isomerism, and the compounds are called isomers.

4.7.1. Examples:

The molecular formula C2H6O has different structural formula.

4.8. Reactivity:

The reaction rates of organic compounds are usually and require specific conditions for their completion.

4.9. Solubility:

Most of organic compounds being largely non polar are insoluble in water, however they are soluble in organic solvents like benzene and ether etc. e.g grease and paints are insoluble in water but they are soluble in petrol.

While some organic compounds are polar in nature and are soluble in water. E.g ethyalcohol are soluble in water.

4.10. Conductivity:

Organic compounds do not conduct electricity.