If hexane (c6h14), octane (c8h18), and octanol (c8h17oh) are heated evenly at different altitudes, rank them according to the order in which you would expect them to begin boiling.

           At different altitudes the Hexane will boil first, followed by octane and octanol will boil at last.

Explanation:
                     The difference in the boiling point of these compounds is mainly due to difference in the intermolecular interactions found in them.
                     Hexane boils first as compared to other two because the interactions present in it are London Dispersion forces which is too present in octane but weaker than octane as the strength of London Dispersion forces increases with increase in carbon chain.
                      Octanol will have the greatest boiling point because it also has Hydrogen bond interactions along with London Dispersion forces which are considered the strongest intermolecular forces.

Which of the following did you identify correctly

While unproven, it uses facts to support part of a conclusion. it is still factual and has predictive power, however.