The total number of cyclic structural isomers (excluding stereoisomers) possible for the molecular formula C ₅ H ₁₀ is

Step-by-step solution

The degree of unsaturation for C ₅ H ₁₀ is 5 + 1 - 10 2 = 1 . Since we are looking for cyclic isomers, the structures must contain exactly one ring. The possible cyclic structural isomers are: 1. Cyclopentane (5-membered ring) 2. Methylcyclobutane (4-membered ring) 3. Ethylcyclopropane (3-membered ring) 4. 1,1-dimethylcyclopropane (3-membered ring) 5. 1,2-dimethylcyclopropane (3-membered ring) Thus, there are 5 cyclic structural isomers. Answer: 5