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For the first-order reaction A -> B + C at 27 deg C, the fraction of reactant molecules able to cross the energy barrier is 3.8 x 10⁻¹⁶ (i.e. 3.8 x 10⁻¹⁶ % expressed as a fraction). Using the Arrhenius/Boltzmann factor, find the activation energy. [log 3.8 = 0.58, 2.303 x 8.314 x 17.42 = 333.33]
- 12 kJ/mole
- 831.4 kJ/mole
- 100 kJ/mole
- 111.11 J/mole
Correct answer: 100 kJ/mole
Solution
Using the fraction 3.8 x 10⁻¹⁸ = e^(-Ea/RT) at 300 K gives Ea approximately 100 kJ/mol with the supplied constants.
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