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Thread: HEAT ABSORBING MATERIALS

  1. #1 HEAT ABSORBING MATERIALS 
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    I would like to find a material that can absorb heat from a bottle of water.
    And basically make the water chill around 3-4 degrees from the room temperature.(25C)
    I know water has a very high specific heat capacity so lots of energy needed to be absorbed to increase its temperature by 1 degree Celsius.
    I just want to make a bottle and surrounded by this type of material or liquid that absorb heat from the content of the bottle( let say the content has in general the same specific heat capacity as water), and make the content chill and ready to serve.
    This is for my Ideas challenge, if you guys have any ideas or know any chemicals that have this physical property
    Please tell me. I would be more than delight.
    Cheers


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  3. #2  
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    The description of your project is very vague. A heat absorbing material? They all do that!

    All you need to do is surround your container with any chilled material and eventually your water sample will have a lower temperature. Of course, some materials are more effective than others, but all must originally be colder than your sample to work.

    Maybe you were asking not about heat-absorbing material but about refrigeration methods? There is magnetic refrigeration and there is acoustic refrigeration. Give us a better idea of your project.
    Â*


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  4. #3  
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    Moderator - This question would be better handled in the Physics forum, y'think?
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  5. #4  
    Forum Freshman rjc34's Avatar
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    from what i get from your description you want to find a material that will absorb heat from a water bottle. We will assume that both will be at room temperature. Therefore, there is no way any traditional material will take away heat when they are already the same heat.

    You do mention chemicals though. An instant cold pack will cool the bottle short term. (so that kind of reaction) I know that sodium acetate packs (HEAT PACKS) care rechargeable (look up the reaction, very cool, it makes hot ice)
    don't know of any rechargeable cold packs, but i bet you could find one.
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  6. #5 heat absorbing material (to clarify) 
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    Thank you for all your ideas.

    I think to use a chilled material to surround the surface of the bottle is not very helpful. How can I let the material surrounded be chilled? I must put it in a fridge. If I can put the material in fridge to let it chill in advance...then y don’t I put the bottle of water in the fridge in advance? No offence but sounds a bit ridiculous.

    Refrigeration method, do you mean to use a noble gas as the material surrounding the bottle? I know that if a gas is pressurized to a liquid, and then if you reduce the pressure and it change back into gas phase, it will absorb loads of energy (heat) for the reason of high latent of vaporization of gas. But this is for refrigeration. I don’t think its possible for a small bottle of soft drink as the volume of the surrounding space of the bottle is small, while the volume of gas is so large. Besides a pressurized liquid is dangerous and may cause explosion. if the container is not hard enough to hold the pressure of the compressed gas.

    I just have a few endothermic reaction in my mind, and I just want to ask you chemists are these reactions ideal to remove heat from the water in the bottle. Cheers
    Lime
    1) CaCO3 -> CaO +H2O
    2) CaO +H2O -> Ca(OH)2
    3) NH4Cl +H2O -> NH4+ + Cl- (aqueous)

    Do you guys have any ideas which reaction sounds better? I put this in chemistry forum as I think chemists are more knowledgeable in chemical reaction.

    When I first come up with an idea...I was thinking of a can food that has material surrounded and carry out exothermic reaction. So the content of the can gets heated up by itself and no flame is needed to cook the food.

    I changed my mind, as I have realized that this idea has been invented by someone else.

    So I moderated the idea and hope it can carry out the "inverse reaction"
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  7. #6  
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    1) CaCO3 -> CaO +CO2 Edit: I corrected your equation (obviously I didn't read it carefullyy before.)

    Yes, endothermic, but the calcium carbonate has to be heated to a very high temperature before it will decompose, so it's no use for chilling water.

    2) CaO +H2O -> Ca(OH)2

    This is lime slaking, which is highly exothermic, not endothermic.

    I don't know about your third example.

    You can chill a bottle of water (or more usually wine) by putting it inside a porous container saturated with water. A terracotta flower pot might do. The water will evaporate and cool the container and its contents by latent heat. The lowest temperature achievable this way will be the wet bulb temperature, which is considerably lower than the dry bulb in dry climates, not so much in humid climates.

    http://www.wineenthusiast.com//E/det...F3DB&AfID=ZNXT
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  8. #7 Lattice enthalpy 
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    Does anyone know the lattice enthalpy..or whatever you call it...the energy of ionization of the following chemical reaction??
    In kJ/mol...it should be a positve number as it is endothermic

    NH4Cl + water => NH4+ + Cl- (aqueous)

    Thanks
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  9. #8  
    Forum Freshman rjc34's Avatar
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    here is an article that gives you all the info you need for that ammonium chloride and water reaction:

    http://72.14.205.104/search?q=cache:...lnk&cd=2&gl=ca
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  10. #9 Cheers 
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    Big thank you to rjc34
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  11. #10  
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    no problem
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