Hazards:
The apparatus is fragile and filled with mercury, please handle it gently.
Chemicals and Solutions:
Materials:
Vapor pressure of water apparatus
Hot plates
Two 4 liter beakers
Meter stick
Procedure:
About 1 hour before classtime, 2/3 fill one beaker with water and heat the water on a hot plate,
Place the other empty beaker on another hotplate and then clamp the vapor pressure of water apparatus so that it is suspended inside the beaker. Make sure the hotplate is OFF.
Show students the vapor pressure of water at room temperature. Then pour the previously heated water into the vessel containing the apparatus. Again measure the vapor pressure and temperature. The water can be heated furthur by turning on the hotplate.
Discussion:
Vapor pressure of water (mm Hg) vs. temperature (ºC)
17.5 mm Hg 20
31.8 mm Hg 30
55.3 mm Hg 40
92.3 mm Hg 50
147 mm Hg 60
233 mm Hg 70
355 mm Hg 80
526 mm Hg 90
760 mm Hg 100
To schedule a demonstration, please send an email to the demonstration lab.
Contact:
Eric Camp
Lecture Demonstration Technician
Bagley Hall 171
(206) 543-1606