Reduced Molar Volume of Real Gas given Wohl Parameter a, and Actual and Reduced Parameters Calculator

Reduced Molar Volume Formula:

\[ V'_r = \frac{V'_m}{\left(\frac{4 \cdot R \cdot \left(\frac{T_{rg}}{T_r}\right)}{15 \cdot \left(\frac{P_{rg}}{P_r}\right)}\right)} \]

Molar Volume of Real Gas (V'm):

m³

Temperature of Real Gas (T_rg):

Reduced Temperature (T_r):

Pressure of Gas (P_rg):

Reduced Pressure (P_r):

Reduced Molar Volume (V'_r):

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1. What is Reduced Molar Volume for P-R Method?

Definition: Reduced Molar Volume for P-R Method of a fluid is computed from the ideal gas law at the substance's critical pressure and temperature per mole.

Purpose: This calculator helps determine the reduced molar volume of real gases using the Peng-Robinson equation of state.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ V'_r = \frac{V'_m}{\left(\frac{4 \cdot R \cdot \left(\frac{T_{rg}}{T_r}\right)}{15 \cdot \left(\frac{P_{rg}}{P_r}\right)}\right)} \]

Where:

\( V'_r \) — Reduced molar volume (dimensionless)
\( V'_m \) — Molar volume of real gas (m³)
\( R \) — Universal gas constant (8.314 J/mol·K)
\( T_{rg} \) — Temperature of real gas (K)
\( T_r \) — Reduced temperature (dimensionless)
\( P_{rg} \) — Pressure of gas (Pa)
\( P_r \) — Reduced pressure (dimensionless)

Explanation: The formula relates the actual molar volume to reduced properties through temperature and pressure ratios.

3. Importance of Reduced Molar Volume Calculation

Details: Reduced properties are essential in thermodynamics for creating generalized correlations that can be applied to many substances.

4. Using the Calculator

Tips: Enter the molar volume of real gas, temperature, reduced temperature, pressure, and reduced pressure. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the Peng-Robinson equation of state?
A: It's a cubic equation of state that provides improved predictions of liquid and vapor phase behavior compared to simpler models.

Q2: Why use reduced properties?
A: Reduced properties allow for generalized correlations that can be applied to many substances using the principle of corresponding states.

Q3: What are typical values for reduced temperature and pressure?
A: Reduced properties are typically between 0 and 1, where 1 represents the critical point.

Q4: How accurate is this calculation?
A: Accuracy depends on how well the substance follows the Peng-Robinson equation of state and the accuracy of input parameters.

Q5: Can this be used for all gases?
A: It works best for non-polar or slightly polar gases. Highly polar or associating fluids may require modifications.