Is There a Relationship Between Density and Boiling Point?

[SuperSandwich]

Just a random question. Is there a specific relationship between density and boiling point? If there is, what is it and why do they relate?

 

[paisiello2]

In general I don't think there is. I believe that molecules that have similar type of chemical bonds (e.g. covalent bonds) in general will have higher boiling points as the density of the pure substance increases.

 

[dauto]

There are two things that play a major role in the boiling point of substances

1: how heavy are the molecules.
2: how strong are the attractive forces between molecules.

 

[mathman]

One additional factor is outside (atmospheric) pressure.

From Wikipedia, the free encyclopedia


Boiling water
The boiling point of a substance is the temperature at which the vapor pressure of the liquid equals the pressure surrounding the liquid[1][2] and the liquid changes into a vapor.

A liquid in a vacuum has a lower boiling point than when that liquid is at atmospheric pressure. A liquid at high-pressure has a higher boiling point than when that liquid is at atmospheric pressure. In other words, the boiling point of a liquid varies depending upon the surrounding environmental pressure. For a given pressure, different liquids boil at different temperatures.

 

[pmacias]

Yes, there is a relationship between density and boiling point. Density is a measure of how tightly packed the molecules of a substance are, while boiling point is the temperature at which a substance changes from a liquid to a gas. The relationship between density and boiling point can be explained by the kinetic molecular theory, which states that as the temperature of a substance increases, the molecules gain more energy and move faster, causing them to spread out and take up more space. This results in a decrease in density. On the other hand, as the temperature increases, the molecules also have a higher chance of overcoming intermolecular forces and escaping into the gas phase, resulting in a higher boiling point. Therefore, there is an inverse relationship between density and boiling point - as density decreases, boiling point increases. This relationship can also be seen in the phase diagram of a substance, where the boiling point is typically higher at lower densities.