Frequency factor

Definition

Frequency factor, also known as the pre-exponential factor, is a term in the Arrhenius equation that represents the frequency of collisions with proper orientation for a reaction to occur. It is denoted by $A$ and has units dependent on the order of the reaction.

5 Must Know Facts For Your Next Test

1. Frequency factor is part of the Arrhenius equation: $k = A e^{-E_a/RT}$.
2. It represents how often molecules collide in the correct orientation to react.
3. Frequency factor is typically determined experimentally.
4. The value of $A$ can vary significantly between different reactions.
5. Higher frequency factors indicate more frequent successful collisions, leading to faster reaction rates.

Review Questions

• What role does the frequency factor play in the Arrhenius equation?
• How does frequency factor affect the rate constant ($k$) of a reaction?
• Why is it important for molecules to collide with proper orientation for a reaction to occur?

Related terms

Arrhenius Equation: An equation that relates the rate constant of a chemical reaction to temperature and activation energy: $k = A e^{-E_a/RT}$.

Activation Energy: The minimum energy required for a chemical reaction to occur, represented as $E_a$ in the Arrhenius equation.

Collision Theory: \text{A theory stating that chemical reactions occur when particles collide with sufficient energy and proper orientation.}