1. The problem statement, all variables and given/known data During the process of fractional distillation, discuss vapour pressure. 2. Relevant equations This is a theoretical question, so I believe no equations are necessary. 3. The attempt at a solution I think that since the bottom of fractional distillation column is the hottest part of the column and is where the crude oil first enters, most of the crude oil components will be in their gaseous form. Therefore, when most of the components are initally in their gaseous form at the bottom of column, the vapour pressure would be highest at the bottom. I think that the vapour pressure would be weakest at the top since the temperature is cooler and most components would have already condensed into their liquid forms in the lower trays. Am I correct?