CHEMISTRY SS 3 NOTE• WEEK: 03 • DATE: 29/09/2014• DURATION: 80MINS• TOPIC: STEREOCHEMISTRY CONTENT

STEREOCHEMISTRY Stereochemistry is the study of structure in three dimensions. Here, we shall

study the phenomenon of isomerism. ISOMERISM

Isomerism is the existence of two or more compounds with the same molecular formula but different structural.

E.g, butane has two Isomers 1. CH3CH2CH2CH3 n-butane

2. CH3CHCH3

CH3

2-methylpropane

ISOMERISM• NOTE: 1. The lsommers with the same homologous series has the same chemical properties but different physical

properties.E.g. n-butane has boiling point of 12oc while 2-Methylpropane boiling point of 0.6oc2. As the number of carbon atom in a molecule increases, the number of isomers also increases. E.g pentane

has three possible isomers, Hexane has five etc

CH3CH2CH2CH2CH3 CH3CH2CHCH3 n-pentane CH3 2-Methylbutane CH3

CH3-C-CH3 CH3 2,2-dimethylpropane

ISOMERISM

However, isomerism occurs in other homologous series where isomers with the sane molecular formula belonging to different

homologous series to have differences physical and chemical properties. E.g Ethanol and Methyloxymethane

ASSIGNMENT Draw all the possible isomers of 1. Hexane 2. Hexene 3. Hexyne