10th Class Science Carbon and its Compounds Crabon and Its Compounds

Crabon and Its Compounds

Category : 10th Class

 Carbon and Its Compounds

 

  • Carbon is a non-metal. All living things, plants and animals are made up of carbon based compounds which are called organic compounds.

We can test the presence of carbon in a material on the basis of the fact that carbon and its compounds burn in air to give carbon dioxide gas which turns lime water milky.

 

  • The atomic number of carbon is 6, i.e., K shell has 2 electrons and L shell has 4 electrons.

 

  • Occurrence of Carbon

Carbon occurs in nature in the 'free state' (as element) as well as in the 'combined state' (in the form of compounds with other elements).

 

  • Allotropes of Carbon

The three allotropes of carbon are diamond, graphite and buck minster fullerene.

 

  • Catenation and Tetravalency

 

  • The two characteristic properties of carbon which leads to the formation of o very large number of organic compounds are catenation and tetravalency.

 

  • Carbon atoms can link with one another by means of covalent bonds to form long chains (or rings) of carbon atoms.

 

  • When carbon atoms combine with one another, three types of chains are formed. These are : (i) straight chains, (ii) branched chains, and (iii) closed chains or ring type chains.

 

  • Hydrocarbons

Hydrocarbons are compounds of carbon and hydrogen. They can be saturated or unsaturated.

 

  • Saturated Hydrocarbons (Alkanes)

 

  • A hydrocarbon in which carbon atoms are bonded to hydrogen atoms by only single bonds is called a saturated hydrocarbon. Saturated hydrocarbons are also called alkanes.

 

  • Unsaturated Hydrocarbons (Alkenes and Alkynes)

A hydrocarbon in which two carbon atoms are bonded by a 'double bond' or a 'triple bond' is called an unsaturated hydrocarbon. Ethene \[({{H}_{2}}C=C{{H}_{2}})\]and ethyne\[(HC\equiv CH)\]are two important unsaturated hydrocarbons, because ethene contains a double bond and ethyne contains a triple bond between two carbon atoms.

 

  • Isomers

The organic compounds having the same molecular formula but different structures are known as isomers. Isomerism is possible only with hydrocarbons having 4 or more carbon atoms.

 

  • Normal-butane has a straight chain structure whereas iso-butane has a branched chain structure.

 

  • Homologous series

A homologous series is a group of organic compounds having similar structures and similar chemical properties in which the successive compounds differ by - CK, group.

 

  • Coal and petroleum

Coal is a complex mixture of compounds of carbon, hydrogen and oxygen, and some free carbon. Small amounts of nitrogen and sulphur compounds are also present in coal.

 

  • Petroleum is a complex mixture of several solid, liquid and gaseous hydrocarbons mixed with water, salt and several particles present in earth's crust.

 

  • Petroleum oil (and natural gas) were formed by the decomposition of the remains of extremely small plants and animals buried under the sea millions of years ago.

 

  • Chemical properties of carbon compounds:

(i) Combustion or burning: Alkanes burn in air to produce a lot of heat due to which alkanes are excellent fuels.

 

(ii) Substitution Reactions: Saturated hydrocarbons, however, undergo substitution reactions with chlorine in the presence of sunlight.

 

(iii) Addition Reactions are undergone by all unsaturated hydrocarbons containing a double bond or a triple bond like the alkenes and alkynes.

 

  • Functional groups

Some of the important functional groups are

 

Name

Functional group

Secondary suffix

Example

Alcohol

- OH

- ol

Ethan + ol = Ethanol

Aldehyde

- CHO

- al

Ethane + al = Ethanal

Ketone

> C = O

- one

Propane + one = Propanone

Carboxylic acid

- COOH

- oic acid

Ethane + oic = Ethanoic acid

Ester

-  COOR

- oate

Methyl + oate = ethanoate

 

  • Soaps and detergents

            Soaps and detergents are sodium salts of different organic acids (or) fatty acids.

 

 

 

Notes - Crabon and Its Compounds


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