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How does sweat evaporate? Answered

 Water turns from liquid to gas at 100ºC. Salt water at an even higher temperature.. Sweat absorbs thermic energy from our skin, which cools the skin and allows the sweat to evaporate.. But how does it reach over 100ºC just from the skin and how comes that we can't feel it?


At 100 C, water CANNOT exist as a liquid or solid. At 0C water cannot exist as a liquid or gas. Between these fixed points water can happily exist in liquid AND gaseous states. Water molecules only need to aquire enough energy to break their bonds in the liquid to turn to vapour.

At 100 c water turns to a gas or steam.  But evaporation will happen even at freezing temperatures.  When water evaporates as ice it think it's called sublimation.

Thanks. I thought the only way to get from liquid to gas was at 100º

How does sweat evaporate? Diffusion.


8 years ago

Actually, your basic statement is wrong. Water or water ice, can vaporize at pretty much any temperature above absolute zero. It just takes longer to do so at lower temperatures. The lower the temperature, the slower the evaporation.
100 degrees C or 212 degrees F indicates the temperature at which water boils at sea level. Boiling and evaporation are two different things but are often confused as being synonymous. Boiling is the point where the temperature at which the vapor pressure in the water is equal to the atmospheric pressure surrounding the liquid.
Evaporation, (or sweating) which can occur at almost any temperature, extracts heat from its  warmer surroundings and thus produce its cooling effect.