Van der Waals Gas Pressure Calculator

Calculate the pressure of a real gas using the van der Waals equation with molecular attraction (a) and volume exclusion (b) correction factors.

Frequently Asked Questions

How does the van der Waals equation improve on the ideal gas law?

It adds a correction a for the attraction between molecules and a correction b for the finite volume the molecules occupy, both of which the ideal gas law ignores.

When do real and ideal pressures diverge most?

They diverge most at high density and low temperature, where molecules are close together and their attractions and finite size matter. At low pressure the two values converge.

Where do the constants a and b come from?

They are measured experimentally and tabulated for each gas. For carbon dioxide a is about 3.64 and b is about 0.0427 in liter and atmosphere units.

Important Disclaimer: Estimates for informational purposes only.

This calculator provides estimates for informational purposes only. Results are based on assumptions and may not reflect actual outcomes. Consult qualified professionals in relevant fields before making important decisions based on these results.