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Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: Hunt on February 24, 2006, 07:32:05 PM

Title: Arrhenius Equation
Post by: Hunt on February 24, 2006, 07:32:05 PM

Does anyone know how to mathematically derive the Arrhenius Equation?

Title: Re:Arrhenius Equation
Post by: madscientist on February 25, 2006, 07:08:08 AM

I can tell you that you start with the van't Hoff equation, Vant_Hoff  ;D
replacing the Delta H rxn with E_A, which is the activation energy.

p.der = partial derivitive

p.der (ln K) / p.der (1/T) = -( Delta H rxn / R )

replacing Delta H rxn with E_A gives:

p.der (ln K) / p.der (1/T) = -( E_A / R )  

by rearranging and integrating both sides you can derive the Arrhenius equation, have a go at doing it and ill work through it with you.

cheers,

madscientist :albert:

Title: Re:Arrhenius Equation
Post by: madscientist on February 25, 2006, 07:12:52 AM

one more hint, the integration constant  "C" is represented by A which is somtimes called the pre-exponential factor.

madscientist :albert:

Title: Re:Arrhenius Equation
Post by: Hunt on February 28, 2006, 04:01:00 PM

I'm very grateful to your reply. A good explanation indeed.