Activation Parameters

To determine a reaction mechanism experimentally, we study the dependence of the rate constant on temperature and pressure to extract the thermodynamic parameters of the transition state:

1. $\Delta H^\ddagger$ (Enthalpy of Activation): The energy required to stretch and weaken bonds. Highly positive values correspond to dissociative processes.
2. $\Delta S^\ddagger$ (Entropy of Activation): Indicates the change in order at the transition state.
   • $\Delta S^\ddagger > 0$: Dissociative (increase in disorder).
   • $\Delta S^\ddagger < 0$: Associative (decrease in disorder).
3. $\Delta V^\ddagger$ (Volume of Activation): The volume change during activation.
   • $\Delta V^\ddagger > 0$: Dissociative (system expands).
   • $\Delta V^\ddagger < 0$: Associative (system contracts).

Use the interactive Eyring Calculator below to input temperature-rate data and extract activation parameters. The calculator automatically performs the linear regression and assigns the mechanism.

Enter (T, k) data pairs and watch the Eyring plot generate automatically. The slope gives $\Delta H^\ddagger$ and the intercept gives $\Delta S^\ddagger$.