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Author Topic: How Does A Chemical Reaction Produce Cold In A Cold Pack ?  (Read 13256 times)

Offline neilep

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Dearest Cold-reaction-ologists,

As a sheepy I of course am used not also as a flotation device but as a bed warmer for many a fair maiden.....it's my raison d'etre to perform as a warmth producer !...so..ewe can imagine my surprise when I had to attend (as a certified First Aider) a young lass who had sprained her ankle....so ..there I was strutting my stuff and I could see that the ankle was swelling so I decided to put a cold pack onto it.


Just like this.


A Cold Pack Just Like This Applied To A Young Fillys Ankle



So, there I was activating the cold pack whilst keeping the young lady calm and then it dawned on me that surely a chemical reaction creates heat...not cold !!...so...what's that all about ?...How does activating this pack make things cold and not hot ?

I asked the young girl many times and all she did was go..”Owwwww” and “ OUCH”....so..no help there !!

If ewe can help me I'll be able to inform this girl next time I see her at Brent Cross Shopping Centre...which is nice !


Hugs & Shmishes


mwah mwah mwah


Neil
My Tummy Is Furry & Warm
xxxxxxxxxxxxxxxxxxxxxxx


 

Offline RD

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How Does A Chemical Reaction Produce Cold In A Cold Pack ?
« Reply #1 on: 29/07/2010 13:24:39 »
surely a chemical reaction creates heat...not cold

Some chemical reactions release heat: exothermic, but others absorb heat : endothermic
 

Offline lightarrow

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How Does A Chemical Reaction Produce Cold In A Cold Pack ?
« Reply #2 on: 29/07/2010 13:29:28 »
I didn't understand if it's the kind of pack with water and a salt. In this case it wouldn't be a chemical reaction but a physical process: dissolving many salts in water requires heat, so the solution becomes colder. Usually it's used the salt ammonium nitrate NH4NO3.

Instead, with a real chemical reaction:
feature=related
feature=related

edit: I've corrected the name nitrate.
« Last Edit: 29/07/2010 18:48:48 by lightarrow »
 

Offline neilep

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How Does A Chemical Reaction Produce Cold In A Cold Pack ?
« Reply #3 on: 29/07/2010 14:01:40 »
surely a chemical reaction creates heat...not cold

Some chemical reactions release heat: exothermic, but others absorb heat : endothermic


Thank Ewe RD..thank ewe very much for the great information.
 

Offline neilep

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How Does A Chemical Reaction Produce Cold In A Cold Pack ?
« Reply #4 on: 29/07/2010 14:05:31 »
I didn't understand if it's the kind of pack with water and a salt. In this case it wouldn't be a chemical reaction but a physical process: dissolving many salts in water requires heat, so the solution becomes colder. Usually it's used the salt ammonium nitride NH4NO3.

Instead, with a real chemical reaction:
feature=related
feature=related

Brilliant...Thank Ewe lightspeed....the links are very helpful...nice vids !!

I'll check the pack to see if the ingredients are listed and also as to whether it's reusable.
 

Offline Joe L. Ogan

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How Does A Chemical Reaction Produce Cold In A Cold Pack ?
« Reply #5 on: 29/07/2010 18:16:15 »
What is a sheepy?  I have seen this term used several times in the various forums and, now, feel like it is time to find out just what is meant by the term.  Thanks for comments.  Joe L. Ogan
« Last Edit: 29/07/2010 18:22:04 by Joe L. Ogan »
 

Offline neilep

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How Does A Chemical Reaction Produce Cold In A Cold Pack ?
« Reply #6 on: 29/07/2010 18:23:53 »
What is a sheepy?  I have seen this term used several times in the various forums and, now, feel like it is time to find out just what is meant by the term.  Thanks for comments.  Joe L. Ogan

A sheepy is what I am ...a woolly four legged  mammalian ruminant
 

Offline Joe L. Ogan

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How Does A Chemical Reaction Produce Cold In A Cold Pack ?
« Reply #7 on: 29/07/2010 18:42:36 »
Would you care to be a little more explicit?  Thanks for comments.  Joe L. Ogan
 

Offline neilep

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How Does A Chemical Reaction Produce Cold In A Cold Pack ?
« Reply #8 on: 29/07/2010 18:50:59 »
Would you care to be a little more explicit?  Thanks for comments.  Joe L. Ogan

Wiki has a good explanation of these animals right here   ;)
 

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How Does A Chemical Reaction Produce Cold In A Cold Pack ?
« Reply #8 on: 29/07/2010 18:50:59 »

 

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