Ideal Gibbs Free Energy using Gibbs Free Energy, Pressure and Fugacity Coefficient Calculator

Ideal Gas Gibbs Free Energy Formula:

\[ G_{ig} = G - [R] \times T \times \ln\left(\frac{f}{P}\right) \]

Gibbs Free Energy (G):

Temperature (T):

Fugacity (f):

Pressure (P):

Ideal Gas Gibbs Free Energy (G_ig): J

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1. What is Ideal Gas Gibbs Free Energy?

Definition: Ideal Gas Gibbs Free Energy is the Gibbs energy in an ideal condition, calculated using the Gibbs free energy of a real system, temperature, and the fugacity-pressure ratio.

Purpose: This calculation helps in thermodynamics to determine the difference between real and ideal gas behavior.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ G_{ig} = G - [R] \times T \times \ln\left(\frac{f}{P}\right) \]

Where:

\( G_{ig} \) — Ideal Gas Gibbs Free Energy (J)
\( G \) — Gibbs Free Energy of the real system (J)
\( [R] \) — Universal gas constant (8.314 J/mol·K)
\( T \) — Temperature (K)
\( f \) — Fugacity (Pa)
\( P \) — Pressure (Pa)

Explanation: The formula calculates the difference between real Gibbs energy and the correction term for non-ideality.

3. Importance of This Calculation

Details: Understanding the ideal gas Gibbs free energy helps in chemical process design, phase equilibrium calculations, and predicting chemical reaction behavior.

4. Using the Calculator

Tips: Enter the Gibbs free energy (J), temperature (K), fugacity (Pa), and pressure (Pa). Temperature and pressure must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is fugacity?
A: Fugacity is a thermodynamic property of a real gas which if substituted for the pressure in equations for an ideal gas gives equations applicable to the real gas.

Q2: Why do we need this calculation?
A: It helps quantify the deviation of real gases from ideal behavior in thermodynamic calculations.

Q3: What units should I use?
A: Use consistent SI units: joules for energy, kelvin for temperature, and pascals for pressure and fugacity.

Q4: Can I use different pressure units?
A: Yes, but ensure fugacity and pressure use the same units for proper ratio calculation.

Q5: What does a negative result mean?
A: A negative result indicates the ideal gas state has lower Gibbs free energy than the real system at the given conditions.