How To: Boil water at room temperature in a vacuum

Boil water at room temperature in a vacuum

This is a super cool way to learn some science while combating spring break or summer break boredom. This science video teaches you how to boil water at room temperature. Obviously this won't work in the normal conditions in which you boil water. But if you place the water in a vacuum, where the atmospheric vapor pressure is lowered, water can boil at a much lower temperature.

Check out this video to learn how to boil water at room temperature.


Bone head the water does not boil... You are out gassing dissolved gasses. The trick only works once. If you try to "reboil" the water you just outgassed it will do nothing. Depending on the amount of vacuum temperature should lower and eventually freeze.

Sorry shafia but you are wrong. The boiling point of an element or a substance is the temperature at which the vapor pressure of the liquid equals the environmental pressure surrounding the liquid. Therefore if you lower the environmental pressure surrounding an element or substance you lower the boiling point at which it will boil, and the inverse if you higher the pressure you higher the boiling point requiring a higher heat to boil. The simplest example is the pressure cooker, taking advantage of this it makes water boil at a higher temperature than in a pot without a cover. I'm a chemist so I know what I'm talking about. The reason you out gas the dissolved gasses is because those dissolved gasses lower their boiling point and since it's boiling point is much lower than water it will boil over first. The trick always works, and it will always work if you have a strong enough vacuum. A normal vacuum wont work. At 760 millimeters of mercury water boils at 100c or 212f, and at 17 millimeters of mercury water boils at 20c or 68f, or more commonly the lowest end of what is considered room temperature. At 4 millimeters of mercury water boils at -2c, and even at an extreme 0.01 millimeters of mercury water will boil at -67c. That's basic refrigeration, and I really suggest you ask one of your local refrigeration experts before you go ahead and dispute my claims.

Thanks Justin for the breakdown / definition! I've been doing HVAC for over 20 + years and have been dealing with inches of mercury on site, but have never heard (or read) it phrased in millimeters of mercury - thanks again, they say ya learn something new every day..

Share Your Thoughts

  • Hot
  • Latest