Step 1: Understanding the Concept:
Structural isomers are compounds with the same molecular formula but different arrangements of atoms. For alkenes, this includes position isomers (double bond location) and chain isomers (branching).
Step 2: Key Formula or Approach:
Start with the longest carbon chain (5 carbons) and move the double bond. Then, shorten the chain to 4 carbons and add a methyl branch.
Step 3: Detailed Explanation:
For \(\text{C}_5\text{H}_{10}\), the open-chain alkene isomers are:
1. \(\text{CH}_2=\text{CH-CH}_2\text{-CH}_2\text{-CH}_3\) (Pent-1-ene)
2. \(\text{CH}_3\text{-CH=CH-CH}_2\text{-CH}_3\) (Pent-2-ene)
3. \(\text{CH}_2=\text{C}(\text{CH}_3)\text{-CH}_2\text{-CH}_3\) (2-Methylbut-1-ene)
4. \(\text{CH}_3\text{-C}(\text{CH}_3)\text{=CH-CH}_3\) (2-Methylbut-2-ene)
5. \(\text{CH}_2=\text{CH-CH}(\text{CH}_3)\text{-CH}_3\) (3-Methylbut-1-ene)
Step 4: Final Answer:
There are 5 structural isomers.