Answer
There are 3 structural isomers of $n-hexene$ formed by moving the position of the double bond. They are:
1. $CH_2=CH-CH_2-CH_2-CH_2-CH_3$
2. $CH_3-CH=CH-CH_2-CH_2-CH_3$
3. $CH_3-CH_2-CH=CH-CH_2-CH_3$
Work Step by Step
Since the hexyne molecule is linearly symmetrical, and the carbon chain is numbered to give the lowest number to the double bond, there can be 3 structural isomers of n-hexene formed by moving the position of the double bond. They are -
1. $CH_2=CH-CH_2-CH_2-CH_2-CH_3 \ ( 1-hexene)$
2. $CH_3-CH=CH-CH_2-CH_2-CH_3 \ ( 2-hexene)$
3. $CH_3-CH_2-CH=CH-CH_2-CH_3 \ ( 3-hexene)$
