Does hot or cold water freeze first?

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Answer by Shannon
Submitted on 5/13/2004
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Contrary to popular opinion, it is possible to have hot water freeze first. If we put two containers with equal amounts of water into the freezer, one hot and one cold, they will both begin loosing heat to the freezer. Normally we would expect the cold water to freeze first, because it has less heat to loose before it reaches the freezing temperature. However, the water can evaporate, and the hot water will evaporate more rapidly than the cold. This is because the molecules in the hot water have more energy than the molecules in the cold water and are moving faster. Because of the evaporation, in the end, there is less water in the container that originally contained hot water. Therefore, there’s less heat to lose in that container and the water freezes first. The chances of seeing this effect are best if the hot water is very hot, perhaps near boiling. Then there will be a lot of evaporation and the difference in volume between the two containers will be large.

Answer by steven
Submitted on 6/4/2006
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Contrary to popular opinion, it is possible to have hot water freeze first. If we put two containers with equal amounts of water into the freezer, one hot and one cold, they will both begin loosing heat to the freezer. Normally we would expect the cold water to freeze first, because it has less heat to loose before it reaches the freezing temperature. However, the water can evaporate, and the hot water will evaporate more rapidly than the cold. This is because the molecules in the hot water have more energy than the molecules in the cold water and are moving faster. Because of the evaporation, in the end, there is less water in the container that originally contained hot water. Therefore, there’s less heat to lose in that container and the water freezes first. The chances of seeing this effect are best if the hot water is very hot, perhaps near boiling. Then there will be a lot of evaporation and the difference in volume between the two containers will be large.

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Question by fgdfgf
Submitted on 3/31/2004
Related FAQ: sci.physics Frequently Asked Questions (Part 1 of 4)
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Does hot or cold water freeze first?

Answer by Liz
Submitted on 4/22/2004
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I actually had to do this experiment for science which really sucked but i did it anyway. In my instance the cold froze first but only marginally before the hot and i did it in an actual freezer not outside so evaporation didn't really have much to do with it.

Answer by Somebody
Submitted on 8/15/2004
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I have 2 do this a science assignment and hot freezes first due to evaporation!

Answer by shellster
Submitted on 8/25/2004
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Cold water freezes faster than hot water. The fact is that hot water does not freeze, that's why it is called HOT water. The water has to go cold before it freezes. So there's your answer- hot water turns into cold water which turns into ice it doesn't go straight from hot to frozen.

Answer by Trevor
Submitted on 10/6/2004
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http://math.ucr.edu/home/baez/physics/General/hot_water.html This is a link to show you this is called, "Mpemba effect"

Answer by nana
Submitted on 10/25/2004
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cold water freezes first is what i found in my expirament

Answer by shea cregger
Submitted on 10/29/2004
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I think it is hot,room tempature.

Answer by josh
Submitted on 11/22/2004
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hot water freeze first

Answer by larry
Submitted on 11/30/2004
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hot will freeze first

Answer by Deshawn
Submitted on 12/2/2004
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All things being equal cold water freezes first

Answer by Answer by Rabia
Submitted on 12/2/2004
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I thought that cold water will freeze first cause not only it is cold cause of the heat now that i know which freezes first its hot water because there is less water in the container that originally contained hot water

Answer by Jamie
Submitted on 12/5/2004
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this question has been very helpful ya know

Answer by Grecia Chapa/Princess Iverson
Submitted on 1/19/2005
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i have to do it for a science project do in two days and i havnt satrted see ya

Answer by babygurl
Submitted on 1/24/2005
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i am doing this for a science project i think cold water would freeze first but, is it. it took about 1 hr. to freeze.cold water frozen first.not hot water

Answer by boxster1
Submitted on 2/4/2005
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Ask any plumber who works in cold weather. Hot water pipes freeze first in the same area as the cold and since they are enclosed in a pipe there goes the evaporation piece.

Answer by lora
Submitted on 10/4/2005
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COLD WATER FREEZES FIRST FOR SURE I'VE DONE IT A COUPLE TIMES AND THE COLD WATER KEPT ON FREEZING FIRST JUST A COUPLE OF MINUTES FOR THE THE HOT WATER TO FREEZE AFTER THE COLD WATER.

Answer by jake
Submitted on 2/18/2005
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I did a lot of reaerch and found out that it was hot water. But when i did the experiment cold water froze 3 out of 5 times. i thought it would be the cold water and i was correct.

Answer by Chloe
Submitted on 2/27/2005
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This is the science project I am doing with my friend Kimmy. I went over to her house and we tested this out. We found out that cold water freezes faster if there is less water and hot water freezes faster if there is more water.

Answer by Kimmy Kim Kim
Submitted on 3/6/2005
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Hi! My name is Kimmy Kim Kim and I am submitting a entry. I actually tested this out and it turned out the if you microwave the hot water for at least five minutes, the water will evaporate when it is in the freezer. Then it will make freezing the water easier so the hot water will win the race.

Answer by Stina
Submitted on 4/30/2005
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I'm doing this for Science right now actually so thanks u guys for your opinions.... i t4tested it before and the cold water started to freeze (top layer) quicker than the hot water but the hot water had ice crystals form on the sides (evaporation). But as a total i got the hot water that froze completely before the cold water did.

Answer by f
Submitted on 5/1/2005
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rfgrgvffcc

Answer by billy bob
Submitted on 5/8/2005
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the hot water freezes before cold water because of the molecules and the energy difference in the molecules. the hot water evaporates quicker therefore cooling quicker and in the end freezing quicker. hot water is quick

Answer by Eric
Submitted on 5/23/2005
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So what you're saying is that I should burn natural gas or propane to heat water up to near boiling point and then put it in my freezer so it can turn on and use electricity: all so i can have ice 10 seconds earlier and less of it. Real smart. Thats a waste of money. I'll just use cold tap water thank you very much

Answer by PIT BULL
Submitted on 6/22/2005
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COLD ALWAYS FREEZES 1ST

Answer by Percy von Strasskoffsky
Submitted on 7/6/2005
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I conducted this experiment as a bit of a laugh. I found boiling water froze much quicker, then room temperature water. Kennedy for Governor

Answer by sunshine
Submitted on 9/20/2005
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i had to do this for a science assignment and the cold water froze first. i put the water in the freezer. i actually used 4 different cups. 2 for each: glass, plastic, paper and stainless steel cups. in all of those cups the cold water froze first. evaporation had nothing to do with it. i found it weird that hot water actually freezes faster than cold water.

Answer by Emily
Submitted on 9/28/2005
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Hot water freezes faster, duh!

Answer by ass licker
Submitted on 9/30/2005
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Answer by Noname
Submitted on 11/3/2005
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Liz is an idiot, the hotter the water the quicker it will freeze, the time the water freezes is dependent on the amount of oxygen in the water. ps: you guys are nerds.... who in the heck stands around and watches water freeze... some one w/o a life is who.

Answer by steve
Submitted on 11/17/2005
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The name of this phenomenon is the Mpemba effect. There are actually many theories for why this happens, for evaporation is not enough to be solely responsible for it. This can be seen if the container is enclosed; no evaporation can occur, but the Mpemba effect still happens. Other possible factors, are convection, supercooling, dissolved gasses, and environmental surroundings. None have been agreed on by scientists.

Answer by julia thenot
Submitted on 12/14/2005
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I did the experiment and the hot water freezes first.I also did the research and it said that hot water goes through a liquid to a gas and solid before the cold water does!

Answer by Brandon D
Submitted on 1/9/2006
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I think hot water freezes before cold water does.

Answer by Shorty
Submitted on 1/16/2006
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I had to this experiment for Science Fair. I tried this experiment OVER AND OVER again just to make sure it wasn't just a coincidence. My results showed that Cold water does in fact freeze faster. While hot water is still trying to freeze cold water is already frozen and is going to the next step which is turning into an ice cube.

Answer by Kenzie
Submitted on 1/18/2006
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I had to do a project (which really sucked) and HOT water freezed faster than cold. I thought the cold water would though.

Answer by Raymend
Submitted on 1/19/2006
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Cold water freezes faster if it is at the wright temature and it depends what each cup of water is set at what temachure

Answer by jalenmj1
Submitted on 1/20/2006
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that whole thing was weak.