How do I know what physical states I should use for different organic compounds?

Hello there,

There is a week until my exams and I’m trying to sort out this problem, since I’m tired of writing perfectly correct equations but being deducted marks for states.

For example, some alkanes are gases, but really large ones I think are liquids. Is there some rule for this? Can I apply it to alkenes too?

And then there are carboxylic acids (which I think are aqueous) and alkanols such as ethanol (anyone have a clue?)

I would greatly appreciate any help!
Thanks