Pressure affecting the latent heat of vapourization

[sgstudent]

Homework Statement

The definition of latent best of vapourization is the amount of thermal energy required to change the state of a liquid to a gas or vice versa. Also, when we increase the pressure of the gas on the liquid there has to be more work done against the surroundings so the latent heat increases. However when they are in the gaseous state will it require less energy for it to reform into a liquid as the pressure around it is greater?

Homework Equations

Q=ml

The Attempt at a Solution

On one hand it makes sense but the definition states that the energy will be the same due to the vice versa. Or is it the same as the gas has more energy than the same gas with a lower pressure surrounding it so when it gives out the energy, there is an excess of it causing more energy to be given out? But still won't the surrounding pressure cause a difference? I'm confused about the two concepts here and it would be great if you guys could sort it out for me.

Thanks for the help!

 

[jbsteele]

The latent heat of vaporization is defined as a constant amount of energy required to change the state of a liquid to a gas or vice versa. The pressure around the liquid or gas does not affect the amount of energy required to change the state. However, when pressure is applied to the liquid or gas, it will affect the temperature at which the state change occurs. For example, an increase in pressure will decrease the boiling point, so it will take less energy to cause the state change.