Calcualting Activation Energy using Arrhenius equation and plot

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SUMMARY

The discussion focuses on calculating activation energy (E_a) using the Arrhenius equation, specifically the formula ln(k) = ln(A) + (-E_a/R)(1/T). The participant plotted ln(k) against 1/T and determined the gradient to be -5525. By applying the relationship between the gradient and activation energy, they calculated E_a to be 45937.6 Joules per mole. Clarification was provided that the units for activation energy are indeed in J/mol, confirming the participant's calculations were correct.

PREREQUISITES
  • Understanding of the Arrhenius equation
  • Knowledge of graphing linear equations
  • Familiarity with units of energy, specifically Joules and Joules per mole
  • Basic concepts of thermodynamics related to activation energy
NEXT STEPS
  • Study the derivation of the Arrhenius equation
  • Learn about the significance of activation energy in chemical kinetics
  • Explore the use of linear regression for data analysis in scientific experiments
  • Investigate the implications of temperature on reaction rates
USEFUL FOR

Chemistry students, laboratory researchers, and anyone involved in chemical kinetics or thermodynamics will benefit from this discussion.

FaraDazed
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This is part of a lab report so not sure if the template agrees with what I am asking but basically using the Arrhenius equation in the form of ln(k)=ln(A)+(\frac{-E_a}{R})(\frac{1}{T}) I plotted a straight line graph of ln(k) vs 1/T and found the gradient to be -5525.

Its the units that are confusing me so not sure if it is as straight forward as what I have done below.
<br /> gradient=\frac{-E_a}{R} \\<br /> (gradient)(R)=-E_a \\<br /> (-5525)(8.3145)=-E_a \\<br /> -45937.6=-Ea \\<br /> ∴ E_a=45937.6 Joules<br />

any help is really appreciated, thanks.
 
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Yes, you did it correctly. The E/RT is dimensionless, so the gradient has units of 1/T, and the activation energy is in J/mole.

Chet
 
Chestermiller said:
Yes, you did it correctly. The E/RT is dimensionless, so the gradient has units of 1/T, and the activation energy is in J/mole.

Chet

Right ok, thanks for clearing that up ie J/mol and not just J. Much appreciated, thanks :)
 

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