1. What is Fugacity Coefficient?

Definition: Fugacity coefficient is the ratio of fugacity to the pressure of that component, measuring how much a real gas deviates from ideal behavior.

Purpose: It's used in thermodynamics to calculate the chemical potential of real gases and in phase equilibrium calculations.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \phi \) — Fugacity coefficient (dimensionless)
• \( G^R \) — Residual Gibbs free energy (J)
• \( R \) — Universal gas constant (8.314 J/mol·K)
• \( T \) — Temperature (K)

Explanation: The residual Gibbs free energy represents the difference between the real and ideal gas Gibbs free energy, and this formula relates it to the fugacity coefficient.

3. Importance of Fugacity Coefficient

Details: Accurate calculation of fugacity coefficients is crucial for modeling phase equilibria, chemical reactions, and thermodynamic properties of real gases and mixtures.

4. Using the Calculator

Tips: Enter the residual Gibbs free energy in joules and temperature in kelvin. Temperature must be > 0 K.

5. Frequently Asked Questions (FAQ)

Q1: What does a fugacity coefficient of 1 mean?
A: A value of 1 indicates ideal gas behavior. Values > 1 indicate positive deviations from ideality, while values < 1 indicate negative deviations.

Q2: How do I obtain residual Gibbs free energy?
A: It can be calculated from equations of state or measured experimentally as the difference between real and ideal gas Gibbs free energy.

Q3: What temperature units should I use?
A: The calculator requires absolute temperature in kelvin (K). Convert from Celsius by adding 273.15.

Q4: What's the range of typical values?
A: For most gases at moderate conditions, φ ranges from 0.9 to 1.1, but can vary more at high pressures or temperatures.

Q5: Can this be used for liquid phases?
A: Yes, the concept applies to both gas and liquid phases, though calculation methods may differ.