Wohl Parameter (b) Formula:
From: | To: |
Definition: Wohl parameter b is an empirical parameter characteristic to equation obtained from Wohl model of real gas.
Purpose: It's used in the Wohl equation of state to describe the behavior of real gases, accounting for molecular volume and intermolecular forces.
The calculator uses the Wohl equation:
Where:
Details: The Wohl parameter b accounts for the finite volume occupied by gas molecules, which becomes significant at high pressures where the ideal gas law fails.
Tips: Enter all required parameters with appropriate units. Default values are provided for common gases, but should be adjusted for specific substances.
Q1: What are typical values for Wohl parameters?
A: Parameters vary by substance. For example, for CO₂: a ≈ 365, b ≈ 0.0427, c ≈ 4.28 × 10⁶.
Q2: When is the Wohl equation most accurate?
A: It works best for moderately non-ideal gases at pressures up to about 10 times critical pressure.
Q3: How do I get critical parameters for my gas?
A: Critical properties are tabulated in chemical engineering handbooks and databases.
Q4: What's the difference between Wohl parameters and van der Waals constants?
A: Both account for molecular interactions, but Wohl's equation uses three parameters (a, b, c) for better accuracy.
Q5: Can I use this for liquid phases?
A: No, the Wohl equation is designed for gas phases only.