Register to reply

How is saturation pressure different than vapor pressure?

by pa5tabear
Tags: pressure, saturation, vapor
Share this thread:
May13-13, 06:00 PM
P: 176
I think I understand, but I want to make sure.

The vapor pressure of a substance is the pressure of the substance evaporating/sublimating at a given temperature and can be calculated using the Antoine Equation. This must be measured at the interface of the substance and atmosphere, or if the system is at equilibrium, it could be measured anywhere in the system.

The saturation pressure assumes that the substance has fully vaporized to its equilibrium point. It could be measured at any gaseous part of the system.

They are almost the same, right? The difference is just whether the system is at equilibrium?
Phys.Org News Partner Chemistry news on
Faster, cheaper tests for sickle cell disease
Simulations for better transparent oxide layers
Characterizing strontium ruthenate crystals for electrochemical applications
May14-13, 02:48 AM
Borek's Avatar
P: 23,600
If I understand your question correctly - yes. We just assume pressure has its maximum possible value at the interface, no matter what is going on in other parts of the system. This is equivalent of assuming there is an equilibrium on the surface.

Register to reply

Related Discussions
Why liquid boils when the envrionmental pressure equals its saturated vapor pressure General Physics 4
Calculating Saturation Vapor Pressure? Classical Physics 0
Saturation pressure of vapor in air General Physics 1
Vapor pressure vs liquid pressure in enthalpic combustion reaction Biology, Chemistry & Other Homework 0
Vapor pressure saturation Biology, Chemistry & Other Homework 4