Uploaded November 2021 | Updated September 2026, 2 weeks ago

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The Handboiler is a fabulous vapor pressure demonstration. When the bottom bulb is placed in your palm, the warmth of your hand makes the air inside the bulb expand and pushes the liquid to the top bulb. In the second video, we sprayed Ethyl Alcohol onto the top bulb. Because evaporation is endothermic, by cooling the top bulb, the air condensed, and the liquid was forced from the higher pressure in the bottom bulb to the lower pressure in the top bulb.
Available here: teachersource.com/product/hand-boiler