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Wohl Parameter (a) of Real Gas using Wohl Equation given Actual and Reduced Parameters Calculator

Wohl Parameter a Formula:

\[ a = \left( \frac{R \cdot T_r \cdot \frac{T}{T_r}}{V'_r \cdot \frac{V_m}{V'_r} - b} + \frac{c}{\left(T_r \cdot \frac{T}{T_r}\right)^2 \cdot \left(V'_r \cdot \frac{V_m}{V'_r}\right)^3} - P_r \cdot \frac{P}{P_r} \right) \cdot \left( T_r \cdot \frac{T}{T_r} \cdot V'_r \cdot \frac{V_m}{V'_r} \cdot \left(V'_r \cdot \frac{V_m}{V'_r} - b\right) \right) \]

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1. What is Wohl Parameter (a) of Real Gas?

Definition: Wohl parameter a is an empirical parameter characteristic to equation obtained from Wohl model of real gas.

Purpose: It helps in describing the behavior of real gases, particularly accounting for intermolecular forces in non-ideal conditions.

2. How Does the Calculator Work?

The calculator uses the Wohl equation:

\[ a = \left( \frac{R \cdot T_r \cdot \frac{T}{T_r}}{V'_r \cdot \frac{V_m}{V'_r} - b} + \frac{c}{\left(T_r \cdot \frac{T}{T_r}\right)^2 \cdot \left(V'_r \cdot \frac{V_m}{V'_r}\right)^3} - P_r \cdot \frac{P}{P_r} \right) \cdot \left( T_r \cdot \frac{T}{T_r} \cdot V'_r \cdot \frac{V_m}{V'_r} \cdot \left(V'_r \cdot \frac{V_m}{V'_r} - b\right) \right) \]

Where:

3. Importance of Wohl Parameter Calculation

Details: Accurate calculation of Wohl parameters is essential for modeling real gas behavior in chemical engineering, thermodynamics, and industrial processes.

4. Using the Calculator

Tips: Enter all required parameters with appropriate units. Default values are provided for reference.

5. Frequently Asked Questions (FAQ)

Q1: What are reduced parameters?
A: Reduced parameters are ratios of actual parameters to their critical values (e.g., reduced temperature = T/Tc).

Q2: How do I find reduced parameters?
A: Divide the actual parameter by its critical value for the substance (available in thermodynamic tables).

Q3: What are typical values for Wohl parameters?
A: Parameters vary by substance. For example, for CO2: a ≈ 0.365, b ≈ 0.0427, c ≈ 0.00042.

Q4: When is the Wohl equation most useful?
A: For moderately non-ideal gases at high pressures and low to moderate temperatures.

Q5: What are the limitations of the Wohl equation?
A: It may not be accurate near the critical point or for highly polar gases.

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