Calculating activation energy using logs

Question

Given that the rate constant is 11 M^-1s^-1 at 345 K and the pre-exponential factor is 20 M^-1s^-1, calculate the activation energy.

Answer 1

k = 20exp(-E_A/RT) (k = 11 at 345K R is 8.314 J/mol-K)

Take ln after dividing through by 20

ln(k/20) = -E_A/RT

Multiply by -RT

E_A = -RTln(k/20) =-(345K)(8.314 J/mol-K)ln(11/20) in Joules/mole (often given in kJ)

Please consider a tutor. Take care.