The rate constant for a certain reaction is measured at two different temperatures:

temperature k
376.0 °C 4.8 x 10^8
280.0 °C 2.3 x 10^8

Assuming the rate constant obeys the Arrhenius equation, calculate the activation energy Ea for this reaction.

Respuesta :

Answer: The activation energy Ea for this reaction is 22689.8 J/mol

Explanation:

According to Arrhenius equation with change in temperature, the formula is as follows.

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

[tex]k_1[/tex] = rate constant at temperature [tex]T_1[/tex] = [tex]2.3\times 10^8[/tex]

[tex]k_2[/tex] = rate constant at temperature [tex]T_2[/tex] = [tex]4.8\times 10^8[/tex]

[tex]E_a[/tex]= activation energy = ?

R= gas constant = 8.314 J/kmol

[tex]T_1[/tex] = temperature = [tex]280.0^0C=(273+280)=553K[/tex]

[tex]T_2[/tex] = temperature = [tex]376.0^0C=(273+376)=649K[/tex]

Putting in the values ::

[tex]ln \frac{4.8\times 10^8}{2.3\times 10^8} = \frac{-E_{a}}{8.314}[\frac{1}{649} - \frac{1}{553}][/tex]

[tex]E_a=22689.8J/mol[/tex]

The activation energy Ea for this reaction is 22689.8 J/mol