2. draw a structural formula for 3,4-hexene (c6h12), which has a double bond between the number 3 and 4 carbons in the chain. what class of compound is it, and what feature distinguishes it as that class?

(C₆H₁₂) 3,4-hexene demonstrating the double bond between 3rd and 4th carbon is shown below:  

CH₃-CH₂-CH=CH-CH₂-CH₃

The suffix ene signifies that it comprises double bond in it between the atoms of carbon that comes under alkene. The Greek prefix hex means 6, and in hexene, it signifies that it comprises six carbon atoms in a molecule. The double bond in the compound is found in between 3 and 4 carbons.  

This can also demonstrate symmetry that comes under symmetrical alkene in such molecule the double bonded carbons exhibit same ligands or a similar number of carbons on both the sides.