Q5. Enthalpy and entropy of activation from the Arrhenius parameters
The Arrhenius activation energy and pre-exponential factor for the reaction H(g) + Br₂(g) → HBr(g) + Br(g) are 15.5 kJ mol⁻¹ and 1.09 × 10¹¹ dm³ mol⁻¹ s⁻¹ respectively. Calculate the standard enthalpy of activation (Δ‡H°) and standard entropy of activation (Δ‡S°) at 1000 K based on a standard state of 1.0 mol dm⁻³. Assume ideal gas behaviour.
Model answer
The free solution for 2023 answers questions 1, 2, 3, 4, 6, 8, 10, 11, 13 and 14, the ones picked in its time plan. Question 5 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
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CoversEyring equationtransition state theoryenthalpy of activationentropy of activationArrhenius parameters