All Questions
Tagged with transition-state-theory thermodynamics
5
questions
3
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0
answers
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Is standard change in activation Gibbs free energy indepedent of pressure?
For a chemical reaction the activation volume is defined as:
$$Δ^{\ddagger}V={V^\ddagger}-V$$
where both $V^\ddagger$ and $V$ refer to standard states (I have omitted the symbol for simplicity). One ...
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4
votes
2
answers
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Why only molecules with three or more atoms undergo unimolecular reaction?
Only molecules with three or more atoms undergo unimolecular reactions. A diatomic molecule cannot dissociate in this way because it has a single mode of vibrational freedom. If this mode is excited ...
- 579
9
votes
1
answer
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Entropy of Activation and Temperature Dependence
I am trying to understand the extrapolation of enthalpy $\Delta H^{\ddagger}$ and entropy of activation $\Delta S^{\ddagger}$ from the Eyring equation. It's typically cast as:
$$\ln\left(\frac{k}{T}\...
2
votes
1
answer
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If Gibbs energy of activation is positive, how is the change to the transition state possible?
The Gibbs energy increases from the reactants to the transition state, but according to the Second Law of Thermodynamics, entropy of the universe can only increase. Why is the transition state ...
- 2,725
14
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3
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Transition state and free energy
We have products $\ce{A + B}$ combining to form $\ce{C + D}$ through the transition state $\ce{X}$.
Are all reactions at least virtually reversible? Is the difference between a reversible reaction ...
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