What does a compressibility factor Z > 1 indicate?

It signifies that molecular repulsive forces and finite molecular excluded volume dominate, making the real gas harder to compress than an ideal gas.

Van der Waals EquationChemistry

Van der Waals Real Gas Equation & Compressibility Factor (Z) Calculator

Calculate non-ideal real gas pressure and compressibility factor (Z) by applying molecular volume exclusion (b) and intermolecular attractive force (a) corrections.

Chemistry & Solutions Gas Laws Thermodynamics

Calculated Result

Van der Waals Real Pressure

21.97bar

Calculator Inputs

Gas Amount in Moles (n)

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Vessel Volume (L)

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Temperature

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Van der Waals Real Pressure

21.97bar

Ideal Gas Predicted Pressure

24.47 bar

Compressibility Factor (Z)

0.9 -

Attractive Forces Dominate (Z < 1): Intermolecular attractions soften wall collisions, depressing real pressure below ideal predictions.

Real vs Ideal Pressure Deviation

Real Pressure

21.97 atm(47%)

Ideal Pressure

24.47 atm(53%)

Advanced physical chemistry and chemical engineering tool for non-ideal real gas behavior.

Calculation Methodology

Van der Waals Equation: [ P + (a * n^2 / V^2) ] * [ V - n * b ] = n * R * T. Real Pressure P = [ nRT / (V - nb) ] - [ an^2 / V^2 ]. Ideal Gas Pressure P_ideal = nRT / V. Compressibility Factor Z = P_real * V / (nRT).

Frequently Asked Questions

At high pressures, gas molecules are forced close together where their physical molecular volume becomes a significant fraction of total space, and attractive intermolecular forces noticeably decrease wall impact force.