1. What is Activation Energy?

Definition: Activation Energy is the minimum amount of energy required to activate atoms or molecules to a condition where they can undergo chemical transformation.

Purpose: This calculator helps determine the activation energy from the slope of an Arrhenius plot (log k vs 1/T).

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( E_a \) — Activation Energy (J/mol)
• \( [R] \) — Universal gas constant (8.314 J/mol·K)
• \( m \) — Slope of line between log K and 1/T (K)

Explanation: The slope from an Arrhenius plot is multiplied by the gas constant and -2.303 to calculate the activation energy.

3. Importance of Activation Energy Calculation

Details: Knowing activation energy helps predict reaction rates, design chemical processes, and understand reaction mechanisms.

4. Using the Calculator

Tips: Enter the slope from your Arrhenius plot (log k vs 1/T graph). The slope should be negative for most reactions.

5. Frequently Asked Questions (FAQ)

Q1: What is the Arrhenius equation?
A: The Arrhenius equation describes how reaction rates depend on temperature: k = A·e^(-Ea/RT).

Q2: Why is the slope negative?
A: The slope is negative because reaction rates typically increase with temperature (1/T decreases as T increases).

Q3: What units should I use for the slope?
A: The slope should be in Kelvin (K) as it comes from a plot of log(k) vs 1/T (where T is in Kelvin).

Q4: What's a typical activation energy range?
A: Most chemical reactions have activation energies between 50-250 kJ/mol (50,000-250,000 J/mol).

Q5: Can I use this for biological systems?
A: Yes, but be aware that enzyme-catalyzed reactions often have lower activation energies than uncatalyzed ones.