Principle

A substance which is gaseous under normal conditions is enclosed
in a variable volume and the variation of pressure with the volume
is recorded at different temperatures. The critical point is
determined graphically from a plot of the isotherms.

Benefits


Visualization of the critical point



Tasks


Measure a number of p-V isotherms of ethane.

Determine the critical point and the critical quantities of
ethane.

Calculate the constants of the Van der Waals equation, the
Boyle temperature, the radius of the molecules and the parameters
of the interaction potential.


What you can learn about


Ideal gases

Real gases

Equations of state

Van der Waals equation

Boyle temperature

Critical point

Interaction potential

Molecule radius