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.
Learning objectives
- Ideal gases
- Real gases
- Equations of state
- Van der Waals equation
- Boyle temperature
- Critical point
- Interaction potential
- Molecule radius