Can I please get an example of how humidity affects evaporation?

1 Answer
May 29, 2018

See Below


So I live in Beijing. When I wash my cloths in the winter (-10C), the cloths will dry very quickly. In the summer, however, it is humid with lots of lightning. Cloths take a lot longer to dry. It is basically Le Chalier's Principle. In the winter when it is cold, the atmosphere has very little water vapor, and so the water vapor is happy to jump off the cloths....and they dry. In the summer, it is the opposite.

I guess you could also say there is a dynamic equilibrium with any solution and its vapor pressure (at a given temperature). If the atmosphere has lots of water in it, then you could make the case that the vapor pressure is higher and the water you want to evaporate can't since equilibrium is already established.

In the winter, the same vapor pressure needs to be established at a given temperature (in an apartment at 25C, for example...with the outside -10C and dry!!). The air in the apartment is dry, and so when the water shows up, it jumps into the air to try to establish that vapor pressure. But the air is really dry, and so the water keeps kicking more and more into the air in a feeble attempt...and after a short time, they water has dried out.