Physical meaning of the extremums of the Van Der Waals equation

[Lindsayyyy]

Hi everyone,

Homework Statement

When I draw an isotherm into a p-V diagram I have to extrem values. If I do an experiment I won't find any extremum, because the van der waals equation isotherm is just theoretical (it's just a line in an experiment).
However, I want to know the 'physical' meaning of the extremums, what do they mean?

Homework Equations

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The Attempt at a Solution

As I don't have statisical mechanics/theoretical thermodynamics during my study I just get to know the basics in thermodynamics. I asked some friends of mine though they don't know the answer either. We thought about the following: When I approch the isotherm from the right I will find a maximum. This could be, because some of the particles start to condensate while others are still gaseous. That was the only idea we got, but I don't think that's the answer.

Can anyone try to help me out?

Thanks for you help

 

[anathema]

and for sharing your question on the forum. The extremums on an isotherm in a p-V diagram represent the points at which the system undergoes a phase transition. This means that the state of the system changes from one phase to another (e.g. from gas to liquid) at these points. These transitions occur due to changes in the intermolecular forces between particles in the system. At the maximum, the system is at the point of saturation, where the gas and liquid phases are in equilibrium. At the minimum, the system is at the point of critical temperature, where the gas and liquid phases have the same density and are indistinguishable.

In an experiment, these points may not be observed because the system may not be at the exact conditions required for a phase transition to occur. However, the van der Waals equation takes into account the effects of intermolecular forces and can show the presence of these extremums. So while they may not be physically observed, they represent important points in the behavior of the system. I hope this helps to clarify the meaning of the extremums on an isotherm.