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Structural Isomerism

Why do only covalently bonded molecules show Isomerism?

The presence of isomerism was observed in all types of compounds; however, Berzelius assigned them different names between 1831 and 1832.

The term allotrope was used to describe different varieties of an element that existed in different physical forms, such as diamond or graphite for carbon or monoclinic or rhombic for sulfur. Polymorphism was used to explain compounds that occurred in more than one crystalline form, like aragonite and calcite, both crystalline forms of calcium carbonate.

History of Isomerism

Accidental discoveries and insatiable curiosity fuel chemistry. 

One such significant discovery is of isomerism, which also occurred around the period when the faith in vitalism, a belief that organic molecules must only come from living organisms, was dwindling. 

It was a pleasant surprise to learn that urea, a by-product of urine produced by human kidneys, could also be synthesized by heating ammonium cyanate, an inorganic compound.

Identify the Functional Isomers of C3H6O- Aldehydes, Ketones and Carboxylic Acids

Question- A and B are two functional isomers of compound C3H6O. On heating with NaOH and I2, Isomer B forms a yellow precipitate of Iodoform whereas Isomer A does not form any precipitate. Write the formulae for A and B.

 

1) Functional Isomers are compounds that have same molecular formula but different functional groups.