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Can Salt Effect How Quick Water Boils?

Introduction and Literature Review A. According to an old wives’ tale adding salt to water will make the water reach its boiling point faster. According to researcher Anne Marie Helmenstine the boiling point of water is 212 degrees Fahrenheit at 1 atmosphere of pressure. But she also states that the boiling point of water depends on the atmospheric pressure. (Helmenstine 2019) Most research shows that a significant amount of salt will be needed to change the boiling point. Lesley-Ann Giddings assistant professor of chemistry at Middlebury College states “You would really have to put a lot of salt in there to make a significant difference” (Giddings 2016) There is a lot of conflicting research on if adding salt will increase or decrease the boiling point but most of it is conclusive that the amount of salt needed would need to be more then a teaspoon. From my research I decided to conduct an experiment by adding a significant amount of salt to water, adding half that amount, and using plain tap water to see if the boiling point was increased or decreased. Introduction and Literature Review A. According to an old wives’ tale adding salt to water will make the water reach its boiling point faster. According to researcher Anne Marie Helmenstine the boiling point of water is 212 degrees Fahrenheit at 1 atmosphere of pressure. But she also states that the boiling point of water depends on the atmospheric pressure. (Helmenstine 2019) Most research shows that a significant amount of salt will be needed to change the boiling point. Lesley-Ann Giddings assistant professor of chemistry at Middlebury College states “You would really have to put a lot of salt in there to make a significant difference” (Giddings 2016) There is a lot of conflicting research on if adding salt will increase or decrease the boiling point but most of it is conclusive that the amount of salt needed would need to be more then a teaspoon. From my research I decided to conduct an experiment by adding a significant amount of salt to water, adding half that amount, and using plain tap water to see if the boiling point was increased or decreased. Section I: Introduction and Literature Review A. My mother has always told me, adding salt to water makes it boil faster! Just as her mother told hers told her and so on. Is it true though? If it even that much of a difference? According to an article on Simplemost.com, “Salt increases water’s boiling point, or the temperature it must reach in order to boil, but This new salt water solution needs more heat to start boiling than pure water does, so the time it takes to boil increases slightly. So your water is hotter, but it’s not boiling any faster.” With this being such an old saying there are many conflicting articles online. I did lots of research and became curious myself… what is the truth? I will experiment by adding different amounts of salt to filtered water and measuring the time it takes to reach boiling point as well as how hot that boiling point is.

Section II: Hypothesis

Can Salt Effect How Quick Water Boils? B. My hypothesis is that the more salt I add to the water the longer it will take to reach a boiling temperature. I will test this theory three different times, once with no salt, a second time with ½ a cup of salt, and a final time with a full cup of salt. All three time the same amount of water will be in the pot, a total of five cups. I also predict that the more salt added the warmer temperature will be due to “saltwater solution needing more heat to start boiling than pure water does”, according to an anonymous author from Simplemost.com. As the water eventually boils in each test, I will mark the temperature it boils at as well as the amount of time it takes to boil. C. My hypothesis that adding salt will slow the boiling processed is based on an article I have read on Livescience.com by author Laura Geggel. The author quotes Middlebury College chemistry Professor Lesley-Ann Giddings, “When salt is added, it makes it harder for the water molecules to escape from the pot and enter the gas phase, which happens when water boils.” The means the boiling point of water with salt must be much higher.

Section III: Method D. The measurement of salt added to the pot of water is my independent variable. Increasing the amounts of salt in the water in each test will be the changing factor. E. The boiling temperature the 5 cups of filtered water need to reach a boiling point, measured by a kitchen thermometer in Fahrenheit is my dependent variable as well as the time it takes to boil, which will be clocked on my phone timer. I am using a total of 5 cups of water and different amounts of salt one cup, ½ cup, and none. F. I will be in control of the amount and type of water used, 5 cups of filtered water per test perfectly measured each time. Using new filtered water and washing the pot after each test will guarantee no errors or mess ups during experimentation. The temperature of the water before each time so that it was the same starting point.

G. Materials needed: o o o o o o

Iodized Salt Filtered Water Metal Pot Phone Timer Measuring Cup Kitchen Thermometer

Can Salt Effect How Quick Water Boils? o Stove Top

H. I begin by pouring 5 cups of filtered water into a metal pot. The temperature of my filtered water was measured at 72 degrees Fahrenheit at the beginning of each test. I started my timer when I placed the pot on the stove and began my first test, my saltless test. The boil time and temperature were recorded. I cleaned and cooled the pot and began test 2 by repeating my pervious actions and adding ½ cup of salt. Temperature and time of boil was recorded. I cleaned and reset my station. I added a full cup of salt in test 3 and Temperature and time of boil was recorded.

Section IV: Result I: Sample 1, 2, and 3, all reached a boiling point. Sample 1 the water without the salt boiled the fastest and at the lowest temperature. Sample 2 the water with 4 tablespoons of salt took the longest to boil and had to reach the highest temperature. Sample 3 the water with 2 tablespoons of water took the second longest and at the second highest temperature. J: Table I: Sample 1, 2, and 3, all reached a boiling point. Sample 1 the water without the salt boiled the fastest and at the lowest temperature. Sample 2 the water with 4 tablespoons of salt took the longest to boil and had to reach the highest temperature. Sample 3 the water with 2 tablespoons of water took the second longest and at the second highest temperature. J: Table I. All 3 tests boiled eventually. As I hypothesized the saltless water begin boiling quicker and did not get as hot. Test 2 with ½ a cup of water took more time than the previous test and did get warmer. Test 3 got the hottest and took much longer to boil.

J. Test

Salt

Temperature (Fahrenheit)

Boiling Point

Test 1

No Salt

187 Degrees

4.32 Minutes

Test 2

½ Cup

203 Degrees

6.45 Minutes

Can Salt Effect How Quick Water Boils? Test 3

1 Cup

224 Degrees

8.53 Minutes

Conclusion K: My hypothesis that the more salt added to water would increase the time and temperature that it took to reach the boiling point was correct. There is a definite consistency in the results as more salt was added the time and temperature at which the water would boil increased. L: The only factor that I could not control for was the atmospheric pressure and the humidity in the air. M: My results are consistent with my research which states that more salt added will increase the temperature and time at which water boils. Sources N: Geggel, Laura, “Does Salt Make Water Boil Faster?” Live Science, September 27, 2016 https://www.livescience.com/amp/56214-does-salt-make-water-boil-faster.html Helmenstine, Anne Marie, Ph.D. "What Is the Boiling Point of Water?" ThoughtCo, Feb. 11, 2020, thoughtco.com/what-is-the-boiling-point-of-water-6 Section V: Conclusions K. My hypothesis that less/no salt would result in boiling point taking less time to reach and a lower overall was correct. The more salt added both the time and temperature increased. L. I could not control the water splashing out of the pot once the boiling point was hit. M. My experimental results follow with my research. Less salt added will decreases temperature and the time it takes water to hit its boiling point. Section VI: Sources N. Anonymous " Newsflash! Salt Does Not Make Water Boil Faster" Simplemost, Dec. 6, 2016, https://www.simplemost.com/newsflash-salt-not-make-water-boil-faster/ Geggel, Laura, “Does Salt Make Water Boil Faster?” Live Science, September 27, 2016 https://www.livescience.com/amp/56214-does-salt-make-water-boil-faster.html...