Kinetics

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Question 13
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For a chemical reaction the relationship between the rate constant, kkk, and the temperature, TTT, is shown by the Arrhenius equation: k=Ae−EaRTk = A e^{-\frac{E_a}{RT}}k=Ae−RTEa​​

For the thermal decomposition of gaseous azomethane:

  • the activation energy, Ea=141 kJ mol−1E_a = 141 \text{ kJ mol}^{-1}Ea​=141 kJ mol−1
  • the Arrhenius constant, A=3.50×1014 s−1A = 3.50 \times 10^{14} \text{ s}^{-1}A=3.50×1014 s−1

At temperature T1T_1T1​ the rate constant, k=1.61×103 s−1k = 1.61 \times 10^3 \text{ s}^{-1}k=1.61×103 s−1

a.

Calculate the temperature T1T_1T1​. The gas constant, R=8.31 J K−1 mol−1R = 8.31 \text{ J K}^{-1} \text{ mol}^{-1}R=8.31 J K−1 mol−1

[4]
b.

Explain why the rate of reaction is faster at a higher temperature T2T_2T2​ than at T1T_1T1​, with reference to the distribution of molecular kinetic energies.

[3]

Kinetics Questions

  1. A Level
  2. /Chemistry
  3. /Kinetics