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?

The correct answer is D. Pentanol is capable of hydrogen bonding, so it goes into the gas phase more easily.

To understand why pentanol has a higher boiling point than hexane, we need to consider the intermolecular forces between molecules. Boiling occurs when the intermolecular forces holding the liquid molecules together are overcome and the molecules transition to the gas phase.

In the case of pentanol, it has an "OH" group attached to one of its carbons, making it an alcohol. This "OH" group allows pentanol to form hydrogen bonds. Hydrogen bonding is a special type of intermolecular force that occurs when a hydrogen atom is bonded to a highly electronegative atom (such as oxygen, nitrogen, or fluorine), and it is attracted to a lone pair of electrons on another molecule. This results in stronger intermolecular forces.

In hexane, on the other hand, there are no functional groups that can form hydrogen bonds. Hexane only experiences weaker intermolecular forces called dispersion forces, which result from temporary shifts in electron density.

Since hydrogen bonding is stronger than dispersion forces, pentanol molecules have stronger intermolecular attractions than hexane molecules. Therefore, pentanol requires more energy to go into the gas phase and has a higher boiling point compared to hexane.