Wohl Parameter (b) Formula:
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Definition: Wohl parameter b is an empirical parameter characteristic to equation obtained from Wohl model of real gas.
Purpose: It helps in describing the behavior of real gases by accounting for molecular size effects in the Wohl equation of state.
The calculator uses the Wohl equation:
Where:
Details: The Wohl parameter b accounts for the finite size of gas molecules in the Wohl equation of state, providing more accurate predictions for real gas behavior compared to ideal gas law.
Tips: Enter all required parameters. Default values are provided for reference. All values must be positive numbers.
Q1: What are typical values for Wohl parameters?
A: Parameters vary by substance. For example, for CO₂: a ≈ 3.59, b ≈ 0.0427, c ≈ 2.30 × 10⁵ (in appropriate units).
Q2: How do I obtain reduced parameters?
A: Reduced parameters are actual values divided by their critical values (e.g., Tr = T/Tc).
Q3: What's the physical significance of parameter b?
A: It represents the volume excluded by a mole of particles, similar to the van der Waals co-volume.
Q4: When is the Wohl equation most accurate?
A: For moderately high pressures and temperatures, where real gas behavior deviates significantly from ideal.
Q5: How does this compare to other equations of state?
A: Wohl's equation is a three-parameter equation that can be more accurate than van der Waals but less complex than Redlich-Kwong or Peng-Robinson.