1. What is Gibbs Free Energy?

Definition: Gibbs Free Energy is a thermodynamic potential that measures the maximum reversible work that may be performed by a thermodynamic system at constant temperature and pressure.

Purpose: It helps predict whether a process will occur spontaneously at constant pressure and temperature.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( G \) — Gibbs Free Energy (J)
• \( G^{ig} \) — Ideal Gas Gibbs Free Energy (J)
• \( R \) — Universal gas constant (8.314 J/mol·K)
• \( T \) — Temperature (K)
• \( f \) — Fugacity (Pa)
• \( P \) — Pressure (Pa)

Explanation: The formula accounts for the deviation from ideal gas behavior using fugacity.

3. Importance of Gibbs Free Energy Calculation

Details: Accurate calculation of Gibbs Free Energy is crucial for understanding chemical reactions, phase transitions, and other thermodynamic processes.

4. Using the Calculator

Tips: Enter the ideal gas Gibbs energy, temperature (must be > 0K), fugacity, and pressure (both must be > 0Pa). The calculator will compute the real Gibbs Free Energy.

5. Frequently Asked Questions (FAQ)

Q1: What is fugacity?
A: Fugacity is a thermodynamic property that measures the "effective pressure" of a real gas, accounting for non-ideal behavior.

Q2: Why do we need both fugacity and pressure?
A: The ratio f/P measures the deviation from ideal gas behavior. For ideal gases, f = P and the correction term becomes zero.

Q3: What units should I use?
A: Use consistent units: Joules for energy, Kelvin for temperature, and Pascals for both fugacity and pressure.

Q4: Can this be used for liquids?
A: Yes, the same formula applies, but you must use appropriate fugacity values for the liquid phase.

Q5: What if I get a negative result?
A: Negative Gibbs energy indicates a spontaneous process under the given conditions.