Free Van der Waals Calculator
Calculate the pressure of a real gas using the Van der Waals equation, which corrects for intermolecular attractions and molecular volume.
mol
K
L
L²·atm/mol²
L/mol
Pressure (Van der Waals)
24.0666 atm
Pressure (Ideal Gas)24.6180 atm
Pressure (Van der Waals) vs Moles of Gas (n)
Van der Waals Equation
Formula
[P + a(n/V)²] × [V - nb] = nRT
Solving for P: P = nRT/(V - nb) − a(n/V)²
Where:
The a term reduces pressure (attraction pulls molecules inward). The b term reduces available volume.
Example Calculation
1 mol of N₂ (a = 1.36, b = 0.0318) at 300 K in 1 L.
- 01P = nRT/(V - nb) - a(n/V)²
- 02P = (1)(0.08206)(300)/(1 - 1×0.0318) - 1.36(1/1)²
- 03P = 24.618/0.9682 - 1.36
- 04P = 25.42 - 1.36
- 05P = 24.06 atm
Frequently Asked Questions
Learn More
Understanding Molarity
Learn what molarity is, how to calculate it, and why it matters in chemistry. Covers moles, liters, dilution, and step-by-step examples for preparing solutions.