hydrocarbons nhexane, cyclohexane, and toluene are are insoluable in H2O (i assume because the hydrocarbons are non polar and water is polar) but why are these three hydrocarbons soluable in CH2Cl2?
Please note the correct spelling (and pronunciation) of soluble (not soluable).
You are exactly right. Those hydrocarbons are not soluble in water because they are non-polar and water is polar. They are soluble in dichlormethane because they are non-polar and dichloromethan is largely non-polar too. (Yes, CH2Cl2 is somewhat polar but not as polar as water; in addition it has some organic--non-polar character--from the CH2 methylene group.