Arrhenius Equation

The Arrhenius equation connects a reaction’s rate constant to temperature by showing that only a fraction of molecules have enough energy to overcome the activation barrier. As temperature increases, the high-energy tail of the molecular energy distribution grows, so successful collisions become much more frequent and k rises exponentially. The factor A bundles collision frequency and orientation effects, while E_a determines how sensitive the reaction is to temperature.

Use this when you need to predict or compare how fast a chemical reaction will be at different temperatures, especially for kinetics, catalysts, and activation-energy calculations. It is also useful for finding E_a from experimental rate constants measured at multiple temperatures.

• Using E_a in kJ mol^-1 without converting to J mol^-1 when R is in J mol^-1 K^-1
• Forgetting that temperature must be in kelvin, not °C
• Treating A as the same as k or assuming it is always equal to the collision frequency