6.04 – The Arrhenius Equation


In this topic, we cover the essential aspects of a successful chemical reaction in terms of reactants colliding.  We will also introduce the Arrhenius equation, which connects the rate constant to the temperature and activation energy for a reaction.

 

Learning Objectives

  • Explain how the activation energy affects a rate and be able to use the Arrhenius equation. (14.5)

To become familiar with the topics presented in this mission, view the slides below and take note of the key ideas.  These are from section 14.5 of your text.

Now work through the practice problems, and post your work to OneNote.

Work through these mastery problems and post your work to OneNote.  The key is available on OneNote also.

14.52  For the elementary process N2O5(g) → NO2(g) + NO3(g) the activation energy (Ea) and overall ΔE are 154 kJ/mol and 136 kJ/mol, respectively.

(a) Sketch the energy profile for this reaction, and label Ea and ΔE.

(b) What is the activation energy for the reverse reaction?

 

14.56  Understanding the high-temperature behavior of nitrogen oxides is essential for controlling pollution generated in automobile engines. The decomposition of nitric oxide (NO) to N2 and O2 is second order with a rate constant of 0.0796 M–1 s–1 at 737°C and 0.0815 M–1 s–1 at 947°C. Calculate the activation energy for the reaction.

 

14.58  The temperature dependence of the rate constant for a reaction is tabulated as follows:

Temperature (K) k (M–1 s–1)
600 0.028
650 0.22
700 1.3
750 6.0
800 23

Calculate Ea and A.

 

2004 FRQ#3

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