The Arrhenius Equation (AQA A-Level Chemistry): Revision Notes

5.2.2 The Arrhenius Equation

The Arrhenius equation links the rate constant with activation energy and temperature.

The rate constant $k$ is influenced by temperature, as described by the Arrhenius equation:

where:

• $A$ is the Arrhenius constant (or pre-exponential factor), representing the frequency of collisions with proper orientation.
• $E_a$ is the activation energy (J mol$⁻¹$), the minimum energy required for the reaction to occur.
• $R$ is the gas constant (8.31 J K$⁻¹$ mol$⁻¹$).
• $T$ is the temperature in Kelvin.

As temperature increases, $e^{-\frac{E_a}{RT}}$ becomes larger, meaning $k$ increases, which in turn increases the rate of reaction.