Is it true?
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Actually, hot water will freeze a bit faster than cold water when both are placed in very cold temperatures due to the lattice structure of water when it is frozen. When water freezes, the water(ice) expands due to the molecules forming a cubic lattice structure. The molecules are farther apart when water is frozen versus when it is a cool liquid. Obviously, when the water is warm, the molecules are farther apart than when the water is cold. Therefore, when water is hot and it molecules are father apart, it is easier for the water to create the cubic lattice structure when being frozen, versus cold water. Note: This isn't true for all possible water temps, only for the temps where the molecule expansion is similiar to the molecular distance between molecules of ice. Kind regards, Tim
If you start with hot water and apply the freezing process, then you get cold water on the way to getting ice. Thus the time taken for hot to ice equals time of hot to cold plus time of cold to ice. The only possible way that freezing hot water could take less time than freezing cold water is if the cold to ice step takes less time if the water was previously hot, i.e., the characteristics of water depend on its history rather than just on its current temperature. I don't know enough physics to comment confidently on this, but I doubt it. John Carson
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If you start with hot water and apply the freezing process, then you get cold water on the way to getting ice. Thus the time taken for hot to ice equals time of hot to cold plus time of cold to ice. The only possible way that freezing hot water could take less time than freezing cold water is if the cold to ice step takes less time if the water was previously hot, i.e., the characteristics of water depend on its history rather than just on its current temperature. I don't know enough physics to comment confidently on this, but I doubt it. John Carson
I don't wanna get to scientific about it, unless you force me. :-) But as Matt said in a thread above its a bit like momentum. Please remember cold water has air inside it as well. One common result of this is cooking with microwaves, after you take the food out of the microwave it continues to cook. Check a microwave cookbook about this if you want. :-) Regardz Colin J Davies
Sonork ID 100.9197:Colin
More about me :-)
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I don't wanna get to scientific about it, unless you force me. :-) But as Matt said in a thread above its a bit like momentum. Please remember cold water has air inside it as well. One common result of this is cooking with microwaves, after you take the food out of the microwave it continues to cook. Check a microwave cookbook about this if you want. :-) Regardz Colin J Davies
Sonork ID 100.9197:Colin
More about me :-)
Colin Davies wrote: Please remember cold water has air inside it as well. But does it have a different amount if it used to be hot? If not, then the hot to ice transition includes a cold to ice transition that is identical to the cold to ice transition that you get if you start with cold water. Colin Davies wrote: One common result of this is cooking with microwaves, after you take the food out of the microwave it continues to cook. That is because it is still hot, not because it is getting hotter. John Carson
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Matt, BTW: boiling water looses its oxygen so when you freeze it, its more solid and clear with less bubbles etc. Regardz Colin J Davies
Sonork ID 100.9197:Colin
More about me :-)
****Colin Davies wrote: BTW: boiling water looses its oxygen so when you freeze it, its more solid and clear with less bubbles etc. Yes and this is also a very good way to get back at a glass container that you are mad at. -Jack To an optimist the glass is half full. To a pessimist the glass is half empty. To a programmer the glass is twice as big as it needs to be.
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Colin Davies wrote: Please remember cold water has air inside it as well. But does it have a different amount if it used to be hot? If not, then the hot to ice transition includes a cold to ice transition that is identical to the cold to ice transition that you get if you start with cold water. Colin Davies wrote: One common result of this is cooking with microwaves, after you take the food out of the microwave it continues to cook. That is because it is still hot, not because it is getting hotter. John Carson
I think we'll only be able to disagree, And I agree that this does not make common sense, nor is it simple logic unfortunatly. Still many of the physical properties of water are not understood by science, which means my argument will dry up somewhere, as I won't be able to explain it, however experimental evidence can prove the assertion. Regardz Colin J Davies
Sonork ID 100.9197:Colin
More about me :-)
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I think we'll only be able to disagree, And I agree that this does not make common sense, nor is it simple logic unfortunatly. Still many of the physical properties of water are not understood by science, which means my argument will dry up somewhere, as I won't be able to explain it, however experimental evidence can prove the assertion. Regardz Colin J Davies
Sonork ID 100.9197:Colin
More about me :-)
I did a quick Google search. Apparently, there are ways in which cold water that used to be hot can differ from water that has been cold from the start. The most important is that more of the water that used to be hot will have evaporated. Thus a smaller volume needs to be frozen (assuming that, in comparing hot to ice and cold to ice, we start with the same initial volume of hot and cold water). Whether a given initial volume of hot water will actually freeze more quickly than a given initial volume of cold water depends on the temperature differences and various other details. It is not a universal result either way. John Carson
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Uhh the movement is directly related to the temperature. pv=nrt right? Chris
Only in a closed system at STP.
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I did a quick Google search. Apparently, there are ways in which cold water that used to be hot can differ from water that has been cold from the start. The most important is that more of the water that used to be hot will have evaporated. Thus a smaller volume needs to be frozen (assuming that, in comparing hot to ice and cold to ice, we start with the same initial volume of hot and cold water). Whether a given initial volume of hot water will actually freeze more quickly than a given initial volume of cold water depends on the temperature differences and various other details. It is not a universal result either way. John Carson
Amazing how such simple stuff can cause this confusion. Here is a link I just posted in the soapbox http://www.sbu.ac.uk/water/explan.html We must be wary also that information that we find on the web is well founded. :-) Best wishes ! Regardz Colin J Davies
Sonork ID 100.9197:Colin
More about me :-)
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I know this has nothing to do with programming, but this is the lounge so i will ask it anyway! ;P Erliar today I was getting ready to boil some water for my dinner when my mother told me that cold water begins to boil sooner then warm/hot water... I am semi-scepticle of this, does anybody know if it is true?:confused:
One thing bothers me about this: You don't cook with water from the hot tap do you? Arrgh! If you can't see anything wrong with this, then consider that in most houses (unless they have some kind of instant wanter heater) that your hot water will be sat around in some kind of storage tank somewhere in your house, whereas the cold water will come directly from the pipes. My Dad's an architect, and he's told me that it's fairly common to find dead pigeons/rats/etc floating in hot water tanks. X| So I'd rather wait the extra minute for the water to boil (assuming it is faster to boil water from the hot tap) -- Help me! I'm turning into a grapefruit!
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One thing bothers me about this: You don't cook with water from the hot tap do you? Arrgh! If you can't see anything wrong with this, then consider that in most houses (unless they have some kind of instant wanter heater) that your hot water will be sat around in some kind of storage tank somewhere in your house, whereas the cold water will come directly from the pipes. My Dad's an architect, and he's told me that it's fairly common to find dead pigeons/rats/etc floating in hot water tanks. X| So I'd rather wait the extra minute for the water to boil (assuming it is faster to boil water from the hot tap) -- Help me! I'm turning into a grapefruit!
I suppose you mean those water tanks that are heated by the sun because here we have closed boilers, and I can understand a rat getting into them (not really probable but ok) but a pigeon, These things are made of steel, use electricity for heating so the only way in or out is trough a 1.5 cm wide tube. btw most of the modern Dutch houses (as mine) come with an instant water heater that also doubles as a central heating system If you would let the water boil propperly it should do you no harm. I would me more afraid of the legionairs disease from not properly heated water in a hot water tank, problem is that this bacteria gets you through your lungs, so taking a shower from such a tank is far more dangerous than drinking a cup of (propperly boiled) tea from it. (the tea colour will also hide the brounish rat color :) )
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I know this has nothing to do with programming, but this is the lounge so i will ask it anyway! ;P Erliar today I was getting ready to boil some water for my dinner when my mother told me that cold water begins to boil sooner then warm/hot water... I am semi-scepticle of this, does anybody know if it is true?:confused:
Freezing and Boiling Tim Smith I know what you're thinking punk, you're thinking did he spell check this document? Well, to tell you the truth I kinda forgot myself in all this excitement. But being this here's CodeProject, the most powerful forums in the world and would blow your head clean off, you've got to ask yourself one question, Do I feel lucky? Well do ya punk?
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I know this has nothing to do with programming, but this is the lounge so i will ask it anyway! ;P Erliar today I was getting ready to boil some water for my dinner when my mother told me that cold water begins to boil sooner then warm/hot water... I am semi-scepticle of this, does anybody know if it is true?:confused:
I don't think that's true. The heat energy required to bring water to boiling is proportional to the temperature difference, so more energy is required to bring cold water to boiling than hot water. The exact amount of heat energy required is:
E = m*s*t + m*L
where m = mass of water s = specific heat (1.0 cal/gm for pure water at sea level) t = temperature difference L = latent heat of vaporization (512 cal/gm I think) /ravi "There is always one more bug..." http://www.ravib.com ravib@ravib.com
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I know this has nothing to do with programming, but this is the lounge so i will ask it anyway! ;P Erliar today I was getting ready to boil some water for my dinner when my mother told me that cold water begins to boil sooner then warm/hot water... I am semi-scepticle of this, does anybody know if it is true?:confused:
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I don't think that's true. The heat energy required to bring water to boiling is proportional to the temperature difference, so more energy is required to bring cold water to boiling than hot water. The exact amount of heat energy required is:
E = m*s*t + m*L
where m = mass of water s = specific heat (1.0 cal/gm for pure water at sea level) t = temperature difference L = latent heat of vaporization (512 cal/gm I think) /ravi "There is always one more bug..." http://www.ravib.com ravib@ravib.com
Here's another question: You have equal amounts of water in do different pots placed over elements of the same temperature, but different sizes. One pot is tall and narrow, with say 5L of water in it, and the other is wide and shallow. Which one will boil sooner, or will it be the same? :~ Don't forget to show your work... Why not throw away a dime? I throw away ten pennies all the time.
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If you throw cold water on a sleeping woman will she boil faster than if you throw warm water on her? :eek: :mad: X| Why not throw away a dime? I throw away ten pennies all the time.
I don't know about her, but I'll be dead. :) /ravi "There is always one more bug..." http://www.ravib.com ravib@ravib.com
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I don't know about her, but I'll be dead. :) /ravi "There is always one more bug..." http://www.ravib.com ravib@ravib.com
Wow this was a heated topic:laugh: (pun intended) I knew it would be thats one reason I asked it and to answer the several factors that Colin brought up I was heating it in a metal (pan)? I guess you could call it that, no the pan was not already heated but the surface of the stove was already hot, but how in the world would I be able to tell if it is highly oxygenated. For Benjymous, I dont know how our water system is set up but if I want hot water I turn the sink knob to point to hot and the water almost instantly becomes hot/warm. I assume I have a different type of water heating system then you... Im glad I received so many replies this has been a very intersting thread.:)