Question

Define isomerism how many structual isomers of butane and pentane also draw its structure and name them

Answer 1

Definition of isomers and isomerism:

The compounds which have same molecular formula but different structures are called isomers and the phenomenon is called isomerism.

Structural isomers of Butane and Pentane:

There are two structural isomers of Butane, namely as follows:

• Common or Trivial name: n-Butane or IUPAC name: Butane; and
• Common or Trivial name: Iso-butane or IUPAC name: 2-Methylpropane

There are three structural isomers of Pentane, namely as follows:

• Common or Trivial name: n-Pentane or IUPAC name: Pentane;
• Common or Trivial name: Iso-pentane or IUPAC name: 2-Methylbutane
• Common or Trivial name: Neo-pentane or IUPAC name: 2,2-Dimethylpropane.

Structures are attached to this answer.

Answer 2

Isomerism, the existence of molecules that have the same numbers of the same kinds of atoms (and hence the same formula) but differ in chemical and physical properties.

Pentane has three structural isomers that are n-pentane, Iso-pentane (methyl butane) and neopentane (dimethylpropane).