How does table salt increase the boiling temperature of water?

It increases the boiling temperature (although not really all that much). A few teaspoons of salt, like you might for cooking, only changes the boiling point 0.5 or 1 degree.

How does the salt do this? That's not a simple question as it turns out, but the explanation below is a pretty good one.

The following is taken from the site listed to the left of this answer, but that page has a lot of additional information, and this is the most important part. This is the real reason the vapor pressure of salt solutions are decreased:

"The reason dissolved solutes (such as salt) increase boiling point is that the solute must come out of solution in order for the water to boil. This costs entropy (the entropy of solution). Boiling is entropically driven, hence the reduction in the net entropy gain of boiling results in a higher temperature needed for the reaction to go. To put it without jargon: for a little packet of water with dissolved salt to turn to steam the salt atoms must, in the course of their random zooming about, ALL simultaneously leave the packet. This is not a likely event. It becomes more likely as the temperature (i.e. the average speed of zooming about) becomes higher, though, and at a certain temperature above the ordinary boiling point it becomes sufficiently likely to allow boiling in spite of the handicap. You can also see that the effect will naturally increase with the concentration of dissolved solutes (i.e. the number of salt atoms per packet that must simultaneously leave)."

See the Related Questions to the left for step by step instructions how to solve boiling point elevation problems and other information.

Answer

How salt efects the boiling point of water is that if you add salt to water then the tempature will get higher because salt helps it get hotter. It helps it get hotter by the ingredents in the salt and more heat there is the more it boils and the more it boils the hotter tempature.

Answer

How salt efects the boiling point of water is that if you add salt to water then the tempature will get higher because salt helps it get hotter. It helps it get hotter by the ingredents in the salt and more heat there is the more it boils and the more it boils the hotter tempature.

First answer by JEK. Last edit by JEK. Contributor trust: 1667 [recommend contributor]. Question popularity: 13 [recommend question]