Calculating Activation Energy Using Slope and the Arhennius Equation

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SUMMARY

The discussion focuses on calculating activation energy (Ea) using the Arrhenius equation, represented as k = A*e^(-Ea/RT). Participants clarify the method of plotting temperature against the natural logarithm of the rate constant (ln(k)) with the x-axis as 1/T. The slope of the resulting linear graph corresponds to -Ea/R, where Ea is the absolute value of the slope multiplied by the gas constant R. This standard linearization technique is confirmed as effective for determining activation energy.

PREREQUISITES
  • Understanding of the Arrhenius equation
  • Familiarity with natural logarithms
  • Basic knowledge of linear regression
  • Concept of the gas constant (R)
NEXT STEPS
  • Study the Arrhenius equation in detail
  • Learn how to perform linear regression analysis
  • Explore the significance of the gas constant (R) in thermodynamics
  • Investigate other methods for calculating activation energy
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Chemists, chemical engineers, and students studying reaction kinetics who need to calculate activation energy using the Arrhenius equation.

relativitydude
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For some reason, this isn't working out.

The Arhennius equation, k = A*e^(-Ea/RT)

I have tables of temperature and k. The book says just calculate it by having the x-axis be 1/T and y-axis be ln(k)

Ok, take Ln of both sides
ln(k) = ln(A*e^(-Ea/RT))
ln(k) = -Ea/RT + ln(A)

Oh, that looks like y = mx + b
 
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So there's actually no problem.It's a standard way of linearizing exponential laws...

Daniel.
 
Ya, I was just being stupid.
 
Note that Ea will be the absolute value of the slope. The slope will be negative, Ea must be positive.
 
Gokul,if you wanted to be strict,u should have mentioned that Ea is the absolute value of the slope TIMES THE GAS CONSTANT "R"...

Daniel.
 
dextercioby said:
Gokul,if you wanted to be strict,u should have mentioned that Ea is the absolute value of the slope TIMES THE GAS CONSTANT "R"...

Daniel.

I should have.

It's common to make the x-axis 1/RT or \beta (when dealing with numbers instead of moles).
 

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