1. What is the Arrhenius Constant for Second Order Reaction?

Definition: The Arrhenius constant (A), also called the frequency factor, represents the frequency of collisions with proper orientation for a second-order chemical reaction.

Purpose: This calculator determines the pre-exponential factor in the Arrhenius equation for second-order reactions.

2. How Does the Calculator Work?

The calculator uses the Arrhenius equation:

Where:

• \( A \) — Arrhenius constant (frequency factor, m³/mol·s)
• \( k \) — Rate constant (m³/mol·s)
• \( E_a \) — Activation energy (J/mol)
• \( R \) — Universal gas constant (8.314 J/mol·K)
• \( T \) — Absolute temperature (K)

Explanation: The equation relates the reaction rate constant to temperature and activation energy.

3. Importance of Arrhenius Constant

Details: The frequency factor helps predict reaction rates at different temperatures and understand reaction mechanisms.

4. Using the Calculator

Tips: Enter the rate constant (k), activation energy (E_a), and temperature (T). All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What are typical values for the Arrhenius constant?
A: For second-order reactions, A typically ranges from 10⁷ to 10¹¹ m³/mol·s.

Q2: How does temperature affect the Arrhenius constant?
A: The Arrhenius constant is theoretically temperature-independent, though it may vary slightly in practice.

Q3: What's the difference between first and second order Arrhenius constants?
A: Second-order constants have units of m³/mol·s, while first-order are in s^-1.

Q4: Can I use this for gas phase reactions?
A: Yes, but ensure your units are consistent (use pressure units if working with gas pressures).

Q5: Why is the exponential term important?
A: It represents the fraction of molecules with sufficient energy to overcome the activation barrier.