If the rate constant for a particular reaction doubles between 20 °C and 40 °C, calculate the value of the activation energy for the reaction.
a. 0.461 kJ
b. 0.231 kJ
c. 261 kJ
d. 26.4 kJ
e. 52.9 kJ
a. 0.461 kJ
b. 0.231 kJ
c. 261 kJ
d. 26.4 kJ
e. 52.9 kJ
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You'll use the Arrhenius equation to calculate Ea.
The equation is:
ln(k2/k1) = -Ea/R(1/T2 - 1/T1)
Since you want the rate to double, k2 will be 2k1, so the ratio of k2/k1 = 2. Also, remember that you must convert your temperatures into Kelvin before using them in the equation, and R will have a value of 8.314 J/mol K. It's a simple matter, then, to calculate Ea.
The equation is:
ln(k2/k1) = -Ea/R(1/T2 - 1/T1)
Since you want the rate to double, k2 will be 2k1, so the ratio of k2/k1 = 2. Also, remember that you must convert your temperatures into Kelvin before using them in the equation, and R will have a value of 8.314 J/mol K. It's a simple matter, then, to calculate Ea.