Medium Practice — Set 2

Quick Recap — Collision Theory, Arrhenius & Catalysis

• Arrhenius: $k=Ae^{-E_a/RT}$; a plot of $\ln k$ vs $1/T$ has slope $-E_a/R$. The fraction of molecules with $E\ge E_a$ is $e^{-E_a/RT}$.
• Collision theory: rate $\propto$ collision frequency $\times$ fraction with $E\ge E_a$ $\times$ orientation (steric) factor.
• Catalyst: provides a lower-$E_a$ path; homogeneous (same phase) or heterogeneous (different phase); does not shift equilibrium.
• Higher $E_a$ reactions are more sensitive to temperature.