1. name one structural and one chemical difference between acetylene and ethylene. give rasons.

2. why is the benzene much less reactive than 1, 3,5-cyclohexatriene?

3. What causes cycloalkanes to have two less hydrogen atoms than similar alkanes that are open chain ones?

1a. double bond in ethylene versus triple bond in acetylene.

b. H atoms on acetylene are more acidic than those of ethylene.

That will get you started. Someone will be glad to comment on your answers to the other two questions.