Actual Pressure of Real Gas given Wohl Parameter a, and Reduced and Critical Parameters Calculator

Pressure of Gas Formula:

\[ P_{gas} = P_r \times \left( \frac{a}{6 \times T_c \times V_c^2} \right) \]

Reduced Pressure (P_r):

Wohl Parameter a:

Critical Temperature (T_c):

Critical Molar Volume (V_c):

m³/mol

Pressure of Gas (P_gas): Pa

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1. What is Actual Pressure of Real Gas Calculator?

Definition: This calculator determines the actual pressure of a real gas using the Wohl equation parameters and critical properties.

Purpose: It helps in thermodynamic calculations where real gas behavior deviates from ideal gas assumptions.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ P_{gas} = P_r \times \left( \frac{a}{6 \times T_c \times V_c^2} \right) \]

Where:

\( P_{gas} \) — Actual pressure of the gas (Pascal)
\( P_r \) — Reduced pressure (dimensionless)
\( a \) — Wohl parameter a (empirical constant)
\( T_c \) — Critical temperature (Kelvin)
\( V_c \) — Critical molar volume (m³/mol)

Explanation: The formula relates the reduced pressure to actual pressure through the gas's critical properties and Wohl parameter.

3. Importance of This Calculation

Details: Accurate pressure calculation is essential for designing chemical processes, pipelines, and storage systems where real gas behavior is significant.

4. Using the Calculator

Tips: Enter the reduced pressure, Wohl parameter a, critical temperature (in K), and critical molar volume (in m³/mol). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is reduced pressure?
A: Reduced pressure is the ratio of actual pressure to critical pressure (P/P_c), making it dimensionless.

Q2: How do I find the Wohl parameter a?
A: Wohl parameters are typically determined experimentally or from thermodynamic tables for specific gases.

Q3: What are typical critical temperature values?
A: Critical temperatures vary widely: ~33 K for hydrogen, 154.6 K for oxygen, 304 K for CO₂, etc.

Q4: Why use critical properties in this calculation?
A: Critical properties define the point where gas and liquid phases become indistinguishable, crucial for real gas behavior.

Q5: What's the accuracy of this calculation?
A: Accuracy depends on how well the Wohl equation models your specific gas. It's most accurate near critical conditions.