Redlich Kwong Parameter given Pressure, Temperature and Molar Volume of Real Gas Calculator

Redlich-Kwong Parameter a Formula:

\[ a = \left(\left(\frac{[R] \times T}{V_m - b}\right) - p\right) \times \left(\sqrt{T} \times V_m \times (V_m + b)\right) \]

Temperature (T):

Molar Volume (V_m):

m³/mol

Redlich-Kwong Parameter b:

Pressure (p):

Redlich-Kwong Parameter a:

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1. What is Redlich-Kwong Parameter a?

Definition: The Redlich-Kwong parameter a is an empirical parameter characteristic to the equation obtained from the Redlich-Kwong model of real gas.

Purpose: It helps in describing the behavior of real gases by accounting for intermolecular forces in the Redlich-Kwong equation of state.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ a = \left(\left(\frac{[R] \times T}{V_m - b}\right) - p\right) \times \left(\sqrt{T} \times V_m \times (V_m + b)\right) \]

Where:

\( a \) — Redlich-Kwong parameter a
\( [R] \) — Universal gas constant (8.314 J/mol·K)
\( T \) — Temperature (Kelvin)
\( V_m \) — Molar volume (m³/mol)
\( b \) — Redlich-Kwong parameter b
\( p \) — Pressure (Pascal)

Explanation: The formula calculates parameter a based on temperature, molar volume, parameter b, and pressure.

3. Importance of Redlich-Kwong Parameters

Details: These parameters are crucial for accurate modeling of real gas behavior, especially at high pressures where ideal gas law fails.

4. Using the Calculator

Tips: Enter temperature in Kelvin, molar volume in m³/mol, parameter b, and pressure in Pascal. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What are typical values for parameter a?
A: Parameter a varies by gas. For example, nitrogen has a ≈ 15.5 Pa·m⁶·K⁰·⁵/mol², while water vapor has a ≈ 142.6 Pa·m⁶·K⁰·⁵/mol².

Q2: How does temperature affect parameter a?
A: The parameter a is temperature-dependent in the Redlich-Kwong equation, decreasing with increasing temperature.

Q3: What's the relationship between a and b parameters?
A: Both parameters account for non-ideal behavior, with a representing intermolecular forces and b representing molecular volume.

Q4: Can I use this for any gas?
A: Yes, but accuracy varies. The Redlich-Kwong equation works best for non-polar or slightly polar gases at moderate pressures.

Q5: Why is the square root of temperature used?
A: The √T term in the Redlich-Kwong equation empirically improves the temperature dependence of the attractive term.