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

Pressure (atm)

Required number input.

Temperature (K)

Required number input.

B(T) (L/mol)

Required number input.

Compute compressibility Z = PV/(nRT) with second virial correction. 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]

Z factor

The resulting z factor returned as a number.

• 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.

• Compressibility Factor Calculator

  Compute Z = PV/(nRT) to quantify deviation of a real gas from ideal behavior.

• Fugacity From Z

  Estimate gas fugacity from a pressure-virial compressibility factor using ln(phi) ≈ Z-1 and f = phi·P; this second-virial approximation is for low pressure.

• Gibbs Surface Excess

  Estimate surface excess Γ from the slope dγ/dln(activity) using Γ=−slope/(nRT). Supply the appropriate ionic/species factor n; the ideal-activity approximation and chosen slope determine the result.