Posted by Anonymous on .
Hexane is a hydrocarbon (a molecule containing only carbon and hydrogen) with a molecular weight of 86.18 g/mol,
a density of 0.660 g/mL, and a boiling point of 69C.
Pentanol is an alcohol (a hydrocarbon with a "OH" group attached to one of its carbons) with a molecular weight of
88.15 g/mol, a density of 0.814 g/mL, and a boiling point of 137C.
Pentanol has the higher boiling point. Why?
A. The higher molecular weight of pentanol results in a higher boiling point.
B. Hexane has stronger intermolecular forces, so it boils at a lower temperature.
C. Hydrogen bonding requires that a pentanol molecule have more energy to escape the liquid phase.
D. Pentanol is capable of hydrogen bonding, so it goes into the gas phase more easily.
E. The dispersion forces in hexane are weaker.
Answered below. I gave you all the hint you need to answer this question. I'm not going to draw a picture.
However, if you wish to do that reading, then pick an answer and tell us why you picked that answer, we shall be happy to critique your thinking.
i would pick c as my choice. since hydrogen bonding is a strong im force it seems that a higher temperature is required to break the bonds. im i right?