Use this chemistry calculator to reproduce a named relationship with explicit quantities and units for study, laboratory planning, or an independent numerical check.

Moles (mol)

Moles of gas.

Volume (L)

Container volume; must exceed n·b.

Temperature (K)

Absolute temperature.

Constant a (atm·L²/mol²)

Attractive-interaction constant.

Constant b (L/mol)

Excluded-volume constant.

Compute the corrected pressure from the van der Waals equation P = nRT/(V−nb) − a(n/V)². The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Pressure (atm)

Corrected pressure.

• The result is conditional on the stated model, constants, standard state, temperature, pressure, composition, and unit basis. Real mixtures and measurements can depart from ideal behavior and carry uncertainty not represented by a single calculated value.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check units and significant figures, compare the result with limiting cases, and use measured or source-specific constants where available. Laboratory, safety, and regulatory decisions require validated methods and appropriate uncertainty analysis.

• Real Gas Correction A Calculator

  Compute van der Waals pressure correction term a(n/V)^2.

• Van der Waals Volume Correction Calculator

  Compute the excluded volume n·b subtracted from container size in the van der Waals equation.

• Real Gas Correction B Calculator

  Compute excluded volume n*b from van der Waals constant b.