1. What is the Equilibrium Constant Calculator?

Definition: This calculator determines the equilibrium constant (K_c) of a chemical reaction based on the Gibbs free energy change and temperature.

Purpose: It helps chemists and students predict the position of equilibrium in chemical reactions under given conditions.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( K_c \) — Equilibrium constant (dimensionless)
• \( \Delta G \) — Gibbs free energy change (J/mol)
• \( R \) — Universal gas constant (8.314 J/mol·K)
• \( T \) — Absolute temperature (Kelvin)

Explanation: The formula relates the thermodynamic driving force (ΔG) to the equilibrium position through the exponential relationship.

3. Importance of Equilibrium Constant

Details: The equilibrium constant quantifies the ratio of product concentrations to reactant concentrations at equilibrium, indicating whether products or reactants are favored.

4. Using the Calculator

Tips: Enter the Gibbs free energy change (ΔG) in J/mol and temperature in Kelvin. Temperature must be > 0 K.

5. Frequently Asked Questions (FAQ)

Q1: What does a large K_c value indicate?
A: K_c > 1 indicates products are favored at equilibrium; K_c < 1 indicates reactants are favored.

Q2: How does temperature affect K_c?
A: For endothermic reactions, K_c increases with temperature; for exothermic reactions, K_c decreases with temperature.

Q3: What are typical units for ΔG?
A: Gibbs free energy is typically expressed in J/mol or kJ/mol (1 kJ = 1000 J).

Q4: Why is the natural logarithm converted to base 10?
A: The factor 2.303 converts from natural log (ln) to base-10 log (log₁₀).

Q5: Can this be used for any reaction?
A: Yes, as long as you have the standard Gibbs free energy change and temperature.