Science, Tech, Math › Science Does Adding Salt Lower the Boiling Point of Water? Effect of Salt on Boiling Point of Water Share Flipboard Email Print Ian O'Leary / Getty Images Science Chemistry Chemistry In Everyday Life Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated October 07, 2019 Does adding salt lower the boiling point of water? You may have heard this and wondered if it was true. Here is a look at the science behind salt and boiling water. Effect of Salt on Boiling Water Adding salt does not lower the boiling point of water. Actually, the opposite is true. Adding salt to water results in a phenomenon called boiling point elevation. The boiling point of water is increased slightly, but not enough that you would notice the temperature difference. The usual boiling point of water is 100 °C or 212 °F at 1 atmosphere of pressure (at sea level). You would have to add 58 grams of salt just to raise the boiling point of a liter of water by one half of a degree Celsius. Basically, the amount of salt people add to water for cooking doesn't affect the boiling point at all. Why does salt affect boiling point? Salt is sodium chloride, which is an ionic compound that breaks apart into its component ions in water. The ions floating around in the water alter how the molecules interact with each other. The effect isn't restricted to salt. Adding any other compound to water (or any liquid) increases its boiling point. Salt in Water Safety Tip If you add salt to water, be sure to add it before boiling the water. Adding salt to water that is already boiling may cause the water to splash up and boil more vigorously for a few seconds. Source Atkins, P. W. (1994). Physical Chemistry (4th ed.). Oxford University Press. ISBN 0-19-269042-6.