Critical Pressure Formula:
From: | To: |
Definition: Critical pressure is the minimum pressure required to liquefy a substance at its critical temperature.
Purpose: This calculator determines the critical pressure using the reduced Wohl equation, which is essential for understanding gas behavior under various conditions.
The calculator uses the reduced Wohl equation:
Where:
Explanation: The equation relates the critical pressure to reduced parameters that describe the gas's state relative to its critical point.
Details: Knowing the critical pressure helps in designing chemical processes, storage systems, and understanding phase behavior of substances.
Tips: Enter the gas pressure in Pascals, reduced temperature, and reduced molar volume. All values must be > 0.
Q1: What are reduced parameters?
A: Reduced parameters are actual conditions divided by their corresponding critical values (temperature, pressure, volume).
Q2: Why use the Wohl equation?
A: The Wohl equation provides a good approximation for real gas behavior, especially near the critical point.
Q3: What units should I use?
A: Pressure should be in Pascals, while reduced temperature and volume are dimensionless ratios.
Q4: How accurate is this calculation?
A: Accuracy depends on how well the Wohl equation describes your specific gas. It's generally good for many common gases.
Q5: What if I get an unrealistic result?
A: Check your input values. Reduced temperature and volume should typically be between 0 and 10 for most practical applications.