1. What is the Arrhenius Equation?

The Arrhenius equation describes the temperature dependence of reaction rates. It shows how the rate constant changes with temperature, providing insight into the activation energy required for a chemical reaction.

2. How Does the Calculator Work?

The calculator uses the Arrhenius equation in two-temperature form:

Where:

• \( k_1 \) — Rate constant at temperature T₁ (1/s)
• \( k_2 \) — Rate constant at temperature T₂ (1/s)
• \( E_a \) — Activation energy (J/mol)
• \( R \) — Universal gas constant (8.314 J/mol·K)
• \( T_1, T_2 \) — Absolute temperatures (K)

Explanation: The equation shows that reaction rates increase exponentially with temperature, with the activation energy determining how sensitive the rate is to temperature changes.

3. Importance of the Arrhenius Equation

Details: The Arrhenius equation is fundamental in chemical kinetics, used to predict reaction rates at different temperatures, determine shelf life of products, and understand reaction mechanisms.

4. Using the Calculator

Tips: Enter known rate constant (k₁) with its temperature (T₁), the second temperature (T₂), and activation energy. All values must be positive numbers. Temperatures must be in Kelvin.

5. Frequently Asked Questions (FAQ)

Q1: How do I convert Celsius to Kelvin?
A: Add 273.15 to the Celsius temperature. For example, 25°C = 298.15 K.

Q2: What is typical activation energy range?
A: Most chemical reactions have Eₐ between 50-250 kJ/mol (50,000-250,000 J/mol).

Q3: Why does rate increase with temperature?
A: Higher temperatures increase the fraction of molecules with sufficient energy to overcome the activation barrier.

Q4: Can this be used for biological systems?
A: Yes, but with caution as biological systems often have complex temperature dependencies.

Q5: What's the relationship between rate constant and half-life?
A: For first-order reactions: t½ = ln(2)/k. The Arrhenius equation thus also predicts how half-life changes with temperature.