[jnimagine]

Which of the following compounds can't be experimented with simple distillation with the addition of sulfuric acid because of poor yield of alkene?
- hydrxyethylbenzene
- cyclohexanol
- 2-propanol
- pentanol

the reasons may be that:
-product is to heavy
- product is too volatile
- substitution happens

any ideas?

[KritikalMass]

I don't even understand your question. But you are reacting alcohols with a strong acid so you are going to get ketones and aldehydes. But like I said not even sure of what your question is 

[Markov]

Please list the desired alkenes (=products of dehydration), along with their boiling points.

Then it will be so much easier to discuss whether they are suitable for distillation or not.
Secondly, we will need to assess whether they are likely to be formed under the conditions.

Also, are you talking about 1-pentanol or other isomer? Also, hydroxyethylbenzene might need some numbers also, to know which isomer we are dealing with.

Also, please list the boiling points of the alcohols themselves, as these boiling ponts are of signifficance, too.

Good Luck!