1. What is Equilibrium Constant for Partial Pressure?

Definition: The equilibrium constant (K_p) expresses the ratio of product partial pressures to reactant partial pressures at equilibrium, each raised to the power of their stoichiometric coefficients.

Purpose: It quantifies the position of equilibrium for gas-phase reactions and helps predict reaction behavior under different conditions.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( K_p \) — Equilibrium constant for partial pressure
• \( \Delta G \) — Gibbs free energy change (Joules)
• \( R \) — Universal gas constant (8.314 J/mol·K)
• \( T \) — Temperature (Kelvin)

Explanation: The formula relates the thermodynamic quantity Gibbs free energy to the equilibrium constant through the exponential function.

3. Importance of Equilibrium Constant Calculation

Details: Knowing K_p helps predict reaction direction, extent of reaction, and the effect of changing conditions on chemical equilibrium.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What does a large K_p value indicate?
A: A large K_p (>1) indicates products are favored at equilibrium, while a small K_p (<1) indicates reactants are favored.

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

Q3: What units should be used for Gibbs free energy?
A: The calculator expects Gibbs free energy in Joules (J). If you have kJ, multiply by 1000 before entering.

Q4: Why is the natural logarithm base used?
A: The relationship between ΔG and K comes from thermodynamic principles where the natural logarithm form appears naturally.

Q5: Can this be used for solutions?
A: No, this calculates K_p for gas-phase reactions. For solutions, use K_c which uses concentrations.