Wednesday, April 24, 2013

Alkanes physical and chemical properties

Introduction :   
Hydrogen atoms in a hydrocarbon aliphatic are perfumed by halogen atoms' consequences in the configuration of alkyl halide and aryl halide correspondingly. Haloalkanes have halogen atoms attached to the SP3 hybridised carbon atoms of an aryl group. Several halogens have organic composite which occur in nature and several of these are clinically useful. These classes of compounds locate wide applications in industry as well as in day-to day life.

Physical properties:

Physical properties:
Alkyl halides will be colourless while pure. Though bromides and iodides expand colour when exposed to light,several volatile halogen compounds contain sweet smell.

Melting and boiling points in physical properties:
Methyl chloride, methyl bromide, ethyl chloride also several chlorofluoromethanes are gas by room temperature. Higher members are liquids or solid. Since, we learnt that the contain, molecules of organic halogen mix are usually polar, suitable to greater polarity as well as higher molecular mass like evaluating to the parent hydrocarbon, the inter molecular forces of attraction are stronger in their halogen derived. The attractions get stronger as the molecules get bigger in size containing  more electrons.

Density in physical properties:
Bromo, iodo and polychloro derived of hydrocarbons are heavier than water. Physical properties of density increases among increase in number of carbon atoms. Halogen atoms with atomic mass of the halogen atoms.

Chemical properties:
Chemical Reactions of alkanes:
The chemical reactions of alkanes may be divided into the following categories:
  • Nucleophilic substitution
  • Elimination reactions
  • Reaction with metals
Nucleophilic substitution in chemical reactions:
A nucleophile reacts with alkane having a partial positive charge on the carbon atom bonded to halogen. A substitution reaction obtain position with halogen atom known leaving group departs as halide ion.

Elimination reactions in chemical reactions:
When an alkane with B-hydrogen atom is heated among alcohilic solution of potassium hydroxide, here is removal of hydrogen atom from B-carbon and a halogen atom from the a-carbon atom.
Alkane is produced the product B-hydrogen atom is occupied in elimination, it is often known B-elimination.

Relation with metals in chemical reactions:
Mainly organic chlorides, bromides and iodides react with definite metals to provide compounds containing carbon-metal bonds. Such compounds are known as organo-metalli compounds.

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