Week 10 Homework Question 15

[Averie Moore 2F]

Calculate the activation energy in kilojoules per mole for a reaction at 55 C that has a rate constant of -0.201 s^-1 and a frequency factor of 9.95 x 10^11 s^-1.

I isolated Ea using the equation to get Ea = - (RT ln(k/A)) but am not getting the correct answer. Did I make a mistake in isolating it or is there a certain order it should be plugged into a calculator?

[406011420 Dis 1C]

Your equation for Ea looks correct to me, I would maybe double check your units? For example, did you convert 55 C to degrees K? And since they want Ea to be in kJ/mol, did you convert your R constant to kJ? You would use 0.008314 as R in case you were not already.

[705903057]

Calculate the activation energy in kilojoules per mole for a reaction at 55 C that has a rate constant of -0.201 s^-1 and a frequency factor of 9.95 x 10^11 s^-1.

For this question, you’ll use the Arrhenius equation. K=Ae^(-Ea/RT)

Rearrange the equation into lnK=-Ea/RT + lnA
LogK= -Ea/2.303RT + logA

And then you’ll plug in your values from there.