Kinectic Theory question

[SayAahh]

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One of my sources states that, as temperature increases, more molecules are moving at higher speeds. And another source says, as temperature increases, FEWER molecules will be moving at the new average speed. Why the discrepancy?

Thanks!

 

[alanan84]

One of my sources states that, as temperature increases, more molecules are moving at higher speeds. And another source says, as temperature increases, FEWER molecules will be moving at the new average speed. Why the discrepancy?

Thanks!

Have you heard of the Maxwell-Boltzmann distribution? It shows the distribution of molecules with certain KE. The only thing that changes it is temp. As temp. increases, the curve kind of flattens out meaning that more molecules have higher kinetic energies and therefore higher average speeds. I believe your first source is correct. Check out this link. Hopefully it works.

http://www.chemistrylecturenotes.com/assets/images/Maxwell-Boltzman__Temp_.jpg

 

[bigstix808]

One of my sources states that, as temperature increases, more molecules are moving at higher speeds. And another source says, as temperature increases, FEWER molecules will be moving at the new average speed. Why the discrepancy?

Thanks!

there is no discrepancy with your statement, its a matter of interpretation. as temperature increase, more molecules are in fact moving at higher speeds by pure definition. at the same time there will also be fewer molecules moving at the new AVERAGE speed because the collision energies are spread over a larger range with more collisions occuring at higher temps

check the chart, that should help visualize.