Question

Which one of the following exhibits ring-chain isomerism?

• A. Hexene and Toluene
• B. Propyne and Cyclopropene
• C. Hexene and Cyclohexane
• D. (b) and (c) above

Answer 1

The correct option is D (b) and (c) above

Compounds with same molecular formula but different mode of linking (open chain or closed chain) of carbon atoms are known as ring-chain isomers.
Hexene and Cyclohexane shows ring-chain isomerism as both have same molecular formula$\left(C_6{H}_{12}\right)$ but different mode of linking of carbon atoms. Hexene is open chain while cyclohexane is closed chain.
Similarly, Propyne and Cyclopropene shows ring-chain isomerism as both have same molecular formula$\left(C_3{H}_4\right)$ but different mode of linking of carbon atoms. Propyne is open chain while cyclopropene is closed chain.