Isomerism Preparation and Properties
→ First of all, isomerism was discovered by Liebig and Wohier in 1820. They observed that the chemical composition of silver fulminate and silver cyanate is same but show different in physical and chemical properties.
→ Similarly, Berzelius and Wohier observed that ammonium cyanate (NH4 CNO) and urea (NH2CONH2) have saine molecular formula but show different physical and chemical their physical and chemical properties. Gay Lussac suggested that the reason for the difference in properties is that the bonding in these compounds is different.
Example : A compound with molecular formula C2H6O can be represented by two forms:
→ In this way, we cannot recognise a compound by molecular formula but its structural formula must be known. Berzelius gave the name ‘isomerism’ to this phenomenon. The compounds having same molecular formula but differ in both physical and chemical properties are called isomers and the phenomenon is called isomerism. The classification of isomerism can be shown by the flow chart:
Flow chart :