Rate constant calculation Using the Arrhenius equation

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To calculate the rate constant at 538 K using the Arrhenius equation, first determine the activation energy (E_a) by applying the equation ln(k2/k1) = -E_a/R(1/T1 - 1/T2) with the given rate constants at 400 K and 450 K. After finding E_a, substitute it back into the Arrhenius equation to solve for the pre-exponential factor (A). Finally, use the values of E_a and A to calculate the rate constant at 538 K using ln(k) = ln(A) - E_a/RT. This method effectively utilizes the relationship between temperature and reaction rates as described by the Arrhenius equation.
Madelin Pierce
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Homework Statement


A reaction has a rate constant of 0.0117/s at 400.0 K and 0.689/s at 450.0 K. What is the value of the rate constant (to 1 decimal place) at 538 K?

Homework Equations


ln k= ln A-E[a]/RT

The Attempt at a Solution


I'm not sure how to approach this problem, although I know the arrhenius equation is involved. When I submitted it blank on the computer, the computer hinted at finding enthalpy. But I don't know how. [/B]
 
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$$\ln{k_1} = \ln{A} - \frac{E_a}{RT_1} \text{...Eqn. 1}$$ and $$\ln{k_2} = \ln{A} - \frac{E_a}{RT_2} \text{...Eqn. 2}$$ for two different ##k_1## and ##k_2## at two different temperatures ##T_1## and ##T_2##.

Subtract Eqn1 from Eqn2:$$\ln{\frac{k2}{k1}} = - E_a R \left(\frac{1}{T_1} - \frac{1}{T_2}\right) \text{...Eqn. 3}$$ Find ##E_a## by putting in the appropriate values.

Then put ##E_a## in Eqn1 or Eqn2, and find ##A##.

Then use $$\ln{k} = \ln{A} - \frac{E_a}{RT}$$ and put ##T= 538K## and find ##k##, the rate constant at temperature ##T##. You already have ##E_a## and ##A##, and they remain constant.
 

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