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Science Fair Presentation
Transcript of Science Fair Presentation
My problem is, “What kind of water freezes the fastest?”
Problem & Topic If I time how long it takes for different types of water to freeze, then, salt water will freeze the fastest because, salt decreases the temperature of water. Hypothesis
The independent variable in my experiment is tap water, sugar water, and salt water.
The dependent variable in my experiment is how long it takes for different types of water to freeze.
The control variables in my experiment are three flexible cups, a freezer, and a measuring cup.
Variables Source 1: “Supercooling Water and Snap Freezing.” Science Fair Project Ideas, & Tools. N.p, n.d. Web. 24 Feb. 2011. http://www.sciencebuddies.org/science-fair-projects/project_ideas/Phys_p033.shtml.
I learned that even solid matter vibrates.
I also learned that the higher the temperature of an object, the faster its molecules move.
In addition, I learned impurities in water cause it to freeze.
Source 2: “Supercool..” University Of Wyoming. N.P., n.d. Web. 24 Feb. 2011. http://faculty.gg.uwyo.edu/kempema/supercool.html.
I learned that when water freezes it gives off a little heat, due to the molecules moving in order to change.
I also learned that when you have cooled water under its freezing point, and drop a piece of ice in it, it freezes instantly.
In addition, I learned that lakes and rivers sometimes naturally go under zero degrees Celsius.
Source 3: “Supercooling – Wikipedia, the free encyclopedia. N.p., n.d. Web. 24 Feb. 2011. http://en.wikipedia.org/wiki/supercooling.
I learned that clouds can carry rain droplets below their freezing point, and cause plains a lot of trouble if they do not have a defrost feature.
I also learned that just like you can keep a liquid from changing to a solid under its freezing point, you can also keep it from changing into a gas by a process called superheating.
In addition, I learned that freezing rain is caused by rain drops under their freezing point.
Materials: You will require tap, salt, and sugar water. In addition you will require 3 flexible plastic cups.
Safety: There are no biological, chemical, or radiological hazards.
• Get your cup(s).
• Pour the sugar in one, the salt in another, and the tap in another.
• After that place you cups in the freezer.
• Set a timer for thirty minutes.
• When the timer goes off insert a toothpick in each, in one’s to thick it is done, continue this process for the others.
Materials, Safety, & Procedure 30 Minutes: All the types of water have formed an ice ring around the cup.
1 Hour: The sugar water has a relatively thick layer on top of it. The salt and sugar really have no progress.
1 Hour 30 Minutes: The sugar water is completely frozen. The sugar and salt water are yet to be finished.
3 Hours: The sugar and salt water are finished in the freezer.
The first time I tried this experiment, I found sugar water freezes the fastest. I also saw tap and salt water took nearly the exact same amount of time to freeze. I deduced sugar makes water freeze a lot faster.
In my second try I got the exact same results. Again the salt and the tap water came in last. Surprisingly the sugar worked its miracle again, and froze in about an hour thirty. I believe the sugar helps thicken the water which then is frozen easily by the freezer.
The ice doesn’t really have a smell. The ice is so cold it doesn’t have a taste. The salt and tap water is mostly. Page 8
clear. The sugar water is mostly a milky color. I think the sugar thickened the water, and slowed the molecules so it was easier to freeze.
In my hypothesis, I thought that salt water would freeze in the shortest period of time, because I thought salt lowered the temperature of water. Once I finished testing my materials two times I found out my hypothesis was incorrect, and that sugar water froze in the shortest amount of time. Both times when I tried it the sugar water froze faster than the others. I had expected the salt water to work because; it usually cools down ice even more so I thought it would help freeze water. I found it odd that the salt water and, the tap water took the longest to freeze.
By doing this experiment I have concluded sugar must help cool even better than salt. Another thing I learned is that using tap water and using salt water are not very different. I also found by doing this experiment either the tap water here is more pure than most so it freezes easily, or salt water and tap water freeze at almost the exact same time. I also think next time I’m trying to cool something with ice, and the procedure is to sprinkle in some salt, I will use sugar instead.
If I ever do this experiment again I would like to try using bottled water instead of tap water. I would like to see if bottled water freezes faster than sugar water because, I learned sugar is good at getting low temperatures, and think bottled water may be good at freezing fast. I also would like to try using boiled water to see if it has fewer impurities so it can freeze faster. Over all I think I will always substitute salt with sugar (except on food). Conclusion Sugar Water Sugar Water Tap Water Tap Water Salt Water