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Author Topic: What is the conceptual picture of endothermic reactions in heat?  (Read 2637 times)

Offline thebrain13

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I was wondering since heat is a measure of average kinetic energy. (a measure of how turbulent the atoms were. What is an endothermic reaction? How is it possible to have negative kinetic energy/turbulence?


 

Offline lightarrow

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I was wondering since heat is a measure of average kinetic energy. (a measure of how turbulent the atoms were. What is an endothermic reaction? How is it possible to have negative kinetic energy/turbulence?
An endothermic reaction is nothing else than a reaction which *exploits* the molecules kinetic energies to happen. The solution of the reagents then becomes colder because the molecules have less kinetic energy; but this energy is not disappeared: it's gone in potential energy of the chemicals.
 

Online yor_on

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Like a fridge.
 

Offline Soul Surfer

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It is not negative.  We live in a dynamic universe Atoms in solids liquids and gasses all possess kinetic energy of motion at all times.  Even at absolute zero in some cases.  The hotter things are the faster the atoms and molecules are moving.

In a exothermic reaction he atoms accelerate towards each other as they combine when they collide so the total speed of the products of the reaction can be greater and therefore hotter. 

In endothermic reactions there is an opposing field slowing down the molecules until they are very close together and then they stick together by very short range forces. This means that the reaction products go away slower and hence colder.  Energy has been absorbed but nothing has had to go negative to do this.
« Last Edit: 12/12/2009 09:23:16 by Soul Surfer »
 

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