SadJoker Posted May 11, 2005 Share Posted May 11, 2005 I'm doing some test corrections and I am stuck on this problem: Many cold packs used for sports injuries are activated by bending the package, causing the substances inside to interact. How does heat flow in this example? Any help is GREATLY appreciated. Link to comment Share on other sites More sharing options...
username Posted May 11, 2005 Share Posted May 11, 2005 it is an endothermic reaction, a chemcial raction that absorbs heat causing the pack to get cold, there lots of info out there on it Link to comment Share on other sites More sharing options...
SadJoker Posted May 11, 2005 Author Share Posted May 11, 2005 it is an endothermic reaction, a chemcial raction that absorbs heat causing the pack to get cold, there lots of info out there on it 585901993[/snapback] I'm not sure if that's what my teacher is looking for, but thanks for your help. :) Link to comment Share on other sites More sharing options...
username Posted May 11, 2005 Share Posted May 11, 2005 http://nobel.scas.bcit.ca/debeck_pt/scienc...ack/pack_p1.htm http://www.google.com/search?hl=en&q=endot...G=Google+Search i know a little bit about science education, what grade are you ;) Link to comment Share on other sites More sharing options...
PseudoRandomDragon Posted May 11, 2005 Share Posted May 11, 2005 The chemicals react with each other. In this reaction, a lot of energy, in the form of heat, is released. Since it loses all the heat, the pack becomes very cold. This is a classic question, expect a similar question on your final. Link to comment Share on other sites More sharing options...
Rob2687 Posted May 11, 2005 Share Posted May 11, 2005 It absorbs heat so it feels cold. If it released heat then it would be a warm pack. Link to comment Share on other sites More sharing options...
Fred Derf Veteran Posted May 11, 2005 Veteran Share Posted May 11, 2005 Homework help should be limited to General Discussion. Link to comment Share on other sites More sharing options...
Laurë Veteran Posted May 11, 2005 Veteran Share Posted May 11, 2005 (edited) The chemicals react with each other. In this reaction, a lot of energy, in the form of heat, is released. Since it loses all the heat, the pack becomes very cold. This is a classic question, expect a similar question on your final. 585902102[/snapback] Completely wrong (<snipped>). The laws of thermodynamics state that heat can not flow from a cooler to a warmer material. It goes from the warmer to the cooler material only. As others have said, this is an endothermic reaction. Heat is going into the pack. Edited May 11, 2005 by fred666 Link to comment Share on other sites More sharing options...
username Posted May 11, 2005 Share Posted May 11, 2005 endothermic: reactacts + heat = product(s) exothermic: reactants = products(s) + heat Link to comment Share on other sites More sharing options...
SadJoker Posted May 11, 2005 Author Share Posted May 11, 2005 It absorbs heat so it feels cold. If it released heat then it would be a warm pack. 585902147[/snapback] Yes, that's what I was looking for. Thanks! :) EDIT: I just realized that's what username said, Rob just worded it differently. Link to comment Share on other sites More sharing options...
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