The rate constant, kkk, for a reaction varies with temperature as shown by the Arrhenius equation:
k=Ae−EaRT k = A \mathrm{e}^{-\frac{E_{\mathrm{a}}}{RT}} k=Ae−RTEaFor this reaction, at 50 ∘C50\text{ }^\circ\text{C}50 ∘C, k=2.45×10−4 s−1k = 2.45 \times 10^{-4}\text{ s}^{-1}k=2.45×10−4 s−1. The activation energy Ea=75.5 kJ mol−1E_{\mathrm{a}} = 75.5\text{ kJ mol}^{-1}Ea=75.5 kJ mol−1. 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.
Calculate a value for the Arrhenius constant, AAA, for this reaction. Give your answer to 3 significant figures and include the appropriate units.
16 exam-style questions on AQA A Level Chemistry Kinetics, covering Collision theory, Maxwell–Boltzmann distribution, Effect of temperature on reaction rate, Effect of concentration and pressure, and Catalysts. Each one has a worked solution and a mark scheme showing where the marks go.