Water <----> Salt

[leolaw]

Originally posted by: WinkOsmosis

Originally posted by: leolaw
Alright, dullard I get this question now, (since i get the required energy to get to the boiling point for the salt water)

And I have another question:

Boiling with 1L of distilled water, after it gets it boiling point, I start adding 1 tablespoon of salt into it, and each time I added the salt, the water rises the temperature w/ 1ºC
WHY?

Because the salt increases the boiling point. When a liquid is boiling, it STAYS at that boiling point. Distilled water that is boiling does not go above 100°C. Add salt, and that boiling point increases.

I know that adding salt into the water would increase the boiling point. That's why I am asking WHY???

 

[white]

Boiling occurs when the evaporation of water molecules becomes so rapid that bubbles of evaporating water molecules form inside the body of the water itself and are able to grow larger and larger, despite the crushing pressure of the surrounding atmosphere. Below water's boiling temperature, any bubble of water vapor that forms inside the body of the water will be smashed almost instantly. But at water's boiling temperature, the pressure of water vapor inside each bubble is high enough to keep the bubble from being crushed. However, adding sugar or salt to the water makes it harder for water molecules to enter one of these water vapor bubbles because the water molecules in the water cling to the salt or sugar molecules and thus don't evaporate as often. With fewer water molecules entering a water vapor bubble, that bubble can't sustain itself and is crushed. Only when you heat the salty or sugary water above the boiling temperature of pure water is there enough evaporation into each water vapor bubble to support it against atmospheric pressure.

http://rabi.phys.virginia.edu/HTW/water_steam_ice.html