Question

Pentane, isopentane and neopentane are a type of:

• A. Geometrical isomerism
• B. Optical isomerism
• C. Positional isomerism
• D. Chain isomerism

Answer 1

The correct option is D Chain isomerism

Structural isomers which have different carbon skeletons
(parent chain or side chain).
Chain isomerism is also known as skeletal isomerism.
These compounds have same molecular, general and emperical formula.
Molecular formula of n-pentane, isopentane (2-methylbutane) and neopentane (2,2-dimethylpropane) are same i.e. $C_5{H}_{12}.$
Pentane exists as three chain isomers: n-pentane, isopentane (2-methylbutane) and neopentane (2,2-dimethylpropane) as shown below: