Question

Which of the following are structural isomers?

• A. 2-methylpropane, propane
• B. Methane, 2-methylpropane
• C. Butane, 2-methylpropane
• D. n-propane, n-butane

Answer 1

The correct option is C Butane, 2-methylpropane

Structural isomers are molecules with same molecular formula but different structures.

The structural formula of methane, ethane and propane reflects that they do not have sufficient carbons to form branched chain. Hence, isomerism is not possible for these compounds.

The compounds butane and 2-methylpropane have same molecular formula ${\text{C}}_4{\text{H}}_{10}$ but posses different structures.




Hence, they are structural isomers.