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This demonstration shows how you can boil water because of reduced pressure without a change in temperature.
* Equipment seen in the video may vary from equipment used in ND Demonstrations. See information and images below for ND equipment and setup.
Setup:
Place a small amount of water in a Pyrex beaker. (Do not use a lot of water as this will take longer and can be damaging to the vacuum pump.)
Place the beaker with water on the vacuum cart under the glass dome.
Turn on the pump to evacuate the chamber.
Once the pressure is low enough, the water will appear to boil despite no change in the temperature.
Notes:
Do not use a lot of water or leave the pump on for an extended period as the humidity is bad for the vacuum pump.
Water will boil until it freezes after 10-15 minutes. Use a small watch glass to minimize heat absorption. Pump oil may need to be changed to reduce moisture in the system for this to occur.
Use a thermometer to illustrate water temperature decreasing as it boils.
Courses Used In:
Coming Soon
Discussion and Polling Questions:
Coming Soon
Equipment Needed:
Vacuum Pump Cart
Glass Dome
Pyrex Beaker
Water
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