Formula:
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Definition: The Van der Waals Constant b represents the volume occupied by one mole of gas molecules and accounts for the finite size of gas particles in the Van der Waals equation.
Purpose: It's a crucial parameter in real gas calculations, correcting the ideal gas law for molecular volume.
The calculator uses the formula:
Where:
Explanation: The critical volume is divided by 3 to estimate the excluded volume parameter in the Van der Waals equation.
Details: This constant is essential for accurate gas behavior predictions, especially at high pressures where molecular volume becomes significant.
Tips: Enter the critical volume in cubic meters (m³). The value must be > 0.
Q1: What's the physical meaning of constant b?
A: It represents the volume actually occupied by gas molecules per mole, making it unavailable for free motion.
Q2: Why divide critical volume by 3?
A: This empirical relationship comes from the theoretical derivation connecting critical parameters to Van der Waals constants.
Q3: What units should I use?
A: Use SI units - cubic meters (m³) for volume, results will be in m³/mol.
Q4: How accurate is this calculation?
A: It provides a good estimate, but exact values may vary slightly for different substances.
Q5: Where can I find critical volume data?
A: Critical volumes are typically found in chemical engineering handbooks or thermodynamic tables.