Hexane ([tex]\( C_6H_{14} \)[/tex]) is an alkane with six carbon atoms. Due to the structure of alkanes, there can be several different ways that these six carbon atoms can be arranged, leading to different structural isomers.
Let's determine the number of possible structural isomers for hexane:
1. Full-length chain isomer: This is the straight-chain version of hexane, where all six carbon atoms are in a continuous chain. This isomer is known as n-hexane.
2. One branch isomer: In this arrangement, five carbon atoms form the main chain, and one carbon atom branches off from one of the middle carbons—a structure often referred to as 2-methylpentane or isohexane.
3. Another one branch isomer: Still with five carbon atoms in the main chain, but the branch is at a different position, resulting in 3-methylpentane.
4. Two branches isomer: Here, trees with four-carbon main chain and two one-carbon branches. This can form 2,2-dimethylbutane.
5. Another two branches isomer: Similarly, a four-carbon main chain but with branches in different positions, forming 2,3-dimethylbutane.
Therefore, hexane has exactly five structural isomers. These different ways to structure the six carbon atoms and fourteen hydrogen atoms result in the following isomer count:
- n-hexane
- 2-methylpentane
- 3-methylpentane
- 2,2-dimethylbutane
- 2,3-dimethylbutane
So, the correct answer to the question is:
five
