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Jun29-04, 10:24 PM
P: 1,780

Also, since k is a function of temperature, if [tex]k_{1}[/tex] and [tex]k_{2}[/tex] are rate constants measured at [tex]T_{1}[/tex] and [tex]T_{2}[/tex] we have from the Arrhenius Equation,

\frac{k_{2}}{k_{1}} = e^{\frac{E_{a}}{R}(\frac{1}{T_{1}}-\frac{1}{T_{2}})}

So actually this eliminates the need to know the frequency factor A. All you need to know is the rate constants measured at two different temperatures or even their ratio [tex]\frac{k_{2}}{k_{1}}[/tex] and that is enough to get [tex]E_{a}[/tex], which turns out to be,

E_{a} = R\frac{T_{1}T_{2}}{T_{2}-T_{1}}log_{e}\frac{k_{2}}{k_{1}}[/tex]

Please make note of this correction in my previous post.