Al Tobias (wat4y) - Office: Gibson S123 & Physics 218, (434) 924-0538
Demonstrations are cataloged according to PIRA Bibliography
PLEASE REQUEST DEMOS WELL IN ADVANCE
Due to Physics Building renovations, the lead time to set up demo requests has increased due to the need to transport equipment across campus. Please be kind and let me know well ahead of time what you need.
Choose a Topic or Enter a keyword to search:
You have selected the following Demos:
video - Boiling by Cooling
Purpose:To show that water will boil at a temperature below 100C if the pressure above the liquid is reduced below atmosphere.
Bring the water in the flask to a boil, remove from heat and seal with the stopper. Let the water cool for a few seconds to make a good seal and then invert the flask as shown in the second image below. At this point, all of the air in the flask should have been replaced with water vapor from the boiling water. Placing some ice in the concave bottom of the flask causes the water vapor to condense leaving a vacuum in the flask. Once the pressure has been reduced enough, the water will begin to boil.