Maharashtra State PSC Model Paper 2

The correct answer is 5.

• ${\mathrm{C}}_6{\mathrm{H}}_{14}$ is hexane. It has 5 structural isomers like n-hexane, 2-methyl pentane, 3-methyl pentane, 2,2-dimethyl butane, 2,3-dimethyl butane.

Important Point

• Compounds with different physical properties were found to have the same elemental composition and molecular weight. Such compounds were called isomers.
• The below table shows the number of constitutional isomers for each of the acyclic alkanes ${\mathrm{C}}_{\mathit{n}}{\mathrm{H}}_{2\mathit{n}+2}$, where n=1-10.
• If the number of carbon atoms increases, the number of possible constitutional isomers increases rapidly.