Physics Dept. Demonstration Manual

DHT08 - Boiling Under Reduced Pressure

Objective: Shows lowering of the boiling point by reducing the surface pressure on the liquid.


  • 300 ml Beaker with coloured water
  • Vacuum pump
  • Vacuum plate
  • "short" thermometer


Water will boil quickly at the reduced pressure in the beaker. The thermometer, set in the beaker, shows room temperature during boiling.