Is it true that water turns to ice quicker if the water is hot?
461446
I found that cold water (38 degrees Fahrenheit) froze faster than hot water out of the tap (125 degrees F). I chose these two temperatures because (1) they were pretty much what the average amateur ice-cube maker would have readily available and (2) I couldn't find a mercury thermometer that went higher than 125 degrees.\n\nJearl, who is not afflicted with penny-pinching editors like some of the rest of us, was able to get his mitts on a thermocouple that could measure as high as the boiling point, 212 degrees F. He found that water heated to, say, 195 degrees would freeze three to ten minutes faster than water at 140-175 degrees. (There were differences depending on how much water was used, where the thermocouple was placed, and so on.) \n\nJearl suggested that the most likely explanation for this was evaporation: when water cools down from near boiling to the freezing point, as much as 16 percent evaporates away, compared to 7 percent for water at 160 degrees. The smaller the amount of water, of course, the faster it freezes. \n\nIn addition, the water vapor carries away a certain amount of heat. To test this theory, Jearl covered his lab beaker with Saran Wrap to prevent water vapor from escaping. The freezing rate difference was greatly diminished. Conceivably convection (motion within the water) also plays a role.\n\nFascinating as all this no doubt is, all it basically proves is that very hot water freezes more slowly than very VERY hot water. The ordinary fumbler in the fridge, on the other hand, is dealing with temps more like the ones I was measuring, in which case cold freezes faster than hot. I rest my case.
663971
actually you dont need warm water to dissolve ice, once ice is exposed to a higher temperature than its own it will melt, thermodynanics.
280538
Hot...In an open container of skating rink, hot water evaporates more quickly and thus cools more quickly.  At sufficiently high temperatures, evaporation is more important, if equal masses of water are taken at two starting temperatures, more rapid evaporation from the hotter one may diminish its mass enough to compensate for the greater temperature range it must cover to reach freezing.
62870
Cold Water. - Most of the time. \nI have tried and tested this before (Tap Water). The hot water normaly takes about 10 minutes longer. When using Tempratures like 30 degrees and 70 degrees this will begin to vary and warm water might start freezing faster than cold water. \n\nWarm water can in fact sometimes freeze faster than Cold water but it very much depends on the conditions.\n\nWhat you are thinking of is the Mpemba effect. This could be due to a number of factors including but not limited to Evaporation (less water needed to be freezed), Dissolved Gasses and Convection.\n\nFor a lengthy but thorough explanation see the link below.\n(Very reliable references) \nhttp://math.ucr.edu/home/baez/physics/General/hot_water.html
348819
fresh water\nany substance in water increases boiling temp\nthe particles of this substance "get in the way" of the water's gas molecules and makes it "more difficult" for the water to evaporate.\nso really, the myth that adding salt to water when making pasta makes it boil faster it enitrely wrong\nit actually makes it longer, but not by much time (a few extra mins)\nsimilarly, This is why we salt our roads\n the salt dissolves the ice and doesn't let it freeze again because it decreases freezing pt by, again, "getting in the way" of the water forming its 6-sided ring (solid state)\na lower temp (slow down the molucles EVEN MORE) is needed to freeze it
926439
fresh water freezes faster...ps, i gave you best answer on a question
77192
No, adding salt does not make water boil more quickly. The colligative properties of water talk about freezing point depression and boiling point elevation. Water will reach a higher temperature before it boils when it contains salt (or any other dissolved substance).\n\nNucleation is a reasonable point, though. In reality, it's probably going to be hard to detect much of a difference. If you're cooking at high altitudes and you add salt to try to make the water boil faster, you're working against yourself.
297542
well lets see, if cold water is anything above 0 Centigrade and hot water is anything under boiling....my money is on the hot winning. What I can not understand is why you asked?
480166
If you have an equal volume of hot and cold water the cold water will be heavier.  This is because when you heat up a substance it become less dense, and in general when you cool down a substance it becomes more dense.\n\nThe exception to the rule is water though.  Water is most dense at 3 degrees cesius, after that it start to take a crystalin form and when it freezes actualy expands.  \n\nso long as you are not saying that the cold water is 1 degree and the hot water is 3, then the cold water will be heavier\n\n\nBut remeber it is not by much in any case
135812
Well for an eight year old....(sounds like an intelligent one to me though)... The reason water freezes slower is because the particles of salt and sugar get in the way of water making a ice crystal.  Salt takes longer because when dissolved it "ionizes" or breaks apart into 2 particles while sugar remains as one.  Salt having two particles it is able to disturb more molecules of water from making ice crystals. I hope that helps! It excites me to here a child of such a young age interested in such things.
726971
h2o has a higher specific heat, meaning it takes a greater amount of energy to change the temperature of the h2o than the metal.  That is why it takes a long time for lakes to freez, ect.
696743
NO! water will boil faster in the water in an area  above 6,000 feet. At higher elevations, where the atmospheric pressure is much lower, the boiling point is also lower, so it means it will boil faster.\n\nFor example: The boiling point of water is 100 °C (212 °F) at standard pressure. On top of Mount Everest the pressure is about 260 mbar (26 kPa) so the boiling point of water is 69 °C. It means lesser time to arrive to its boiling point.\n\nIf you were to boil water on Mount Everest,it  would be the lowest boiling point in the world because of its high elevation and low air pressure. If you were to boil water at the Dead Sea, it would reach the highest boiling point on Earth due to the low elevation and high air pressure. \n\nElevation affects the boiling point because of the amount of air pressure pushing down on the surface of the water. At a higher elevation the pressure is less and at a lower elevation  it is higher. When the pressure is higher, the molecules must absorb more energy in order to change state from liquid to gas therefore requiring more energy (temperature).♥
621743
We cannot make a substance cold. \n\nWe can remove the heat from one place to another.\n\n  What is the difference between ice and water?\n\nFrom ice we have removed heat. The water is water because we have not removed heat from it. \n\nWe should not say ice is cold when compared to water, because we have not made it cold but we have removed heat from it.\n\nSimilarly when we want some hot coffee, we should ask, I want a coffee in which heat is added because we cannot make coffee hot.\n\nThank you.
494092
As any sane and decent person would expect, hot water out of the tap will boil faster than cold water out of the tap. However, water that has been boiled once and allowed to cool will boil faster than hot water out of the tap. That's because boiling gets rid of the dissolved oxygen usually found in water, making it easier for the water to boil the second time around.
844878
Gases are more soluble in cold water than hot.  So if you take cold water from the faucet and freeze it, the ice will usually be cloudy.  If you heat it up first--or better yet, boil it--then freeze it quickly, without letting it sit around and absorb more gas,  the ice will be clear.
731331
I've heard that its the boiling water that freezes first. \n\nI think because the water molecules are hot (i.e. they are moving fast) the energy (or heat) will escape (move to equilibrium with other items in the freezer) at a faster rate than the water molecules in colder cup of water. \n\nBut really I'm mostly guessing with my explanation.
46526
it doesnt, however the energy is lost faster in hot water than in cooler water.  The rate at which all water freezes is the same.