Vapour Pressure: Pressure Exerted on Liquid & Container

AI Thread Summary
Vapour pressure refers to the pressure of a vapor in equilibrium with its liquid phase in a closed system. It exerts the same pressure on both the container and the liquid, as per Pascal's law, which states that static pressure in fluids is uniform in all directions. The pressure of saturated vapor is temperature-dependent and influenced by the curvature of the liquid surface. At higher altitudes, the pressure exerted on the container decreases due to gravitational effects, as explained by the barometric formula. Understanding these principles is crucial for accurate thermodynamic calculations.
johnathon
Messages
40
Reaction score
0
According to Wikipedia, vapour pressure is the pressure of a vapor in thermodynamic equilibrium with its condensed phases in a closed system.
Does that mean the pressure the vapour exerts on the container or the pressure the vapour exerts on the liquid?
 
Physics news on Phys.org
Jonathon,
if we compare the pressure of saturated vapor on the container at the level of the liquid and the pressure on the liquid, these are the same, by Pascal's law - in fluids, static pressure is the same in all directions. This is the pressure given as "pressure of saturated vapor" in tables (depends on the temperature and the curvature of liquid surface).

If the pressure on the container was considered at higher altitude, this would be lower due to gravity (look for barometric formula).

Jano
 
I have recently been really interested in the derivation of Hamiltons Principle. On my research I found that with the term ##m \cdot \frac{d}{dt} (\frac{dr}{dt} \cdot \delta r) = 0## (1) one may derivate ##\delta \int (T - V) dt = 0## (2). The derivation itself I understood quiet good, but what I don't understand is where the equation (1) came from, because in my research it was just given and not derived from anywhere. Does anybody know where (1) comes from or why from it the...
Back
Top