Q11(b). Activation energy from the slope of an Arrhenius plot
The values of the rate constant (k) for the reaction 2N₂O₅(g) → 4NO₂(g) + O₂(g) were determined at several temperatures. A plot of ln k vs 1/T gave a straight line of which the slope was found to be −1.2 × 10⁴ K. What is the activation energy of the reaction?
Model answer
The free solution for 2024 answers questions 1, 2, 3, 4, 5, 8, 9, 13, 14 and 15, the ones picked in its time plan. Question 11 is answered in full in the Geo-Scientist Chemistry Paper II, 2021 to 2025 book, with every part of every paper.
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UPSC Combined Geo-Scientist (Main) Chemistry Paper II: Model Answers 2021 to 2025
- All fifteen questions of each paper, with the question printed above its answer
- Numericals worked from formula to result with units; graphs with labelled axes
- Topic-wise weightage and a topic-wise index
CoversArrhenius equationactivation energyArrhenius plotN₂O₅ decompositionln k vs 1/T
All parts of Question 11
- 11(a) Time for 99 % and 99.9 % completion of a first-order reaction10 marks
- 11(b) Activation energy from the slope of an Arrhenius plot5 marks
- 11(c) Cell reaction and ΔG, ΔH, ΔS from emf and dE/dT5 marks