Friday, February 25, 2011

Video on Isomerism

Stereoisomerism

-Compounds which have the same molecular formula and structural formula but differ in arrangement of atoms in space.
-Divided into two types: cis-trans isomerism and optical isomers(enantiomers)

Cis-Trans Isomerism
Optical Isomerism
Arises due to restricted arrangement of carbon-carbon double bond and carbon-carbon single bond in cyclic compounds
Carbon molecules with at least one chirality centre(carbon attached to 4 different atoms or groups of atoms)
Has different atoms or groups of atoms at the same C=C bond or C-C bond in cyclic compounds Optically active, exist as enantiomers and not superimposable
Have same chemical properties but different physical properties Able to rotate plane polarised light in a polarimeter

Constitutional Isomerism

-Divided into 3 types: chain, positional and functional group isomerism.

Chain Isomers
Positional Isomers
Functional Group Isomers
Differ in number of longest carbon Differ in position of functional group Differ in type of class
Differ in physical properties
Similar in chemical properties
Differ in physical properties
Similar in chemical properties
Differ in both physical and chemical properties

Functional Group Isomers
Chain Isomers


Positional Isomers

Isomerism

Isomers are compounds which have the same molecular formula but different structural formulae.
There are two types of isomers which in turn subdivides into other isomers as shown below:


Wednesday, February 23, 2011

Introduction To Organic Chemistry

- Organic chemistry: The study of carbon compounds from living thing which contains C, H, O, S, P and halogens(F, Cl, Br, I)

- Essential in all aspects of life whether it is living or non-living matters.

- Have extensive uses in many fields such as medical, agriculture, engineering and biotechnology.

-Can be divided into several subtopics:

Empirical, molecular and structural formulae

Functional groups and homologous series

Isomerism (Covered in the next post)

Organic Reactions