What do van der Waals constants a and b represent?

Parameter a (L²·atm/mol²) represents attractive intermolecular forces reducing effective pressure. Parameter b (L/mol) is excluded volume per mole (4 × actual molecular volume). CO₂: a=3.59, b=0.0427.

When does ideal gas law fail significantly?

Ideal gas fails at high pressure (P > 10 atm) and near critical point. Compressibility factor Z = PV/nRT ≠ 1. Z > 1 at high P (repulsion dominates); Z < 1 at moderate P (attraction dominates).

What is the critical point of a van der Waals gas?

Critical temperature T_c = 8a/(27Rb), critical pressure P_c = a/(27b²), critical volume V_c = 3b. For CO₂: T_c = 304.2K, P_c = 73.8 bar. Above T_c, no liquid-vapor distinction.

Van der Waals Gas Calculator

Apply van der Waals equation (P + a/V²)(V - b) = RT accounting for intermolecular attractions (a) and finite molecular volume (b). Compare with ideal gas. Calculate compressibility factor Z = PV/nRT.

2D stress state at a point. All stresses in MPa.

σx — Normal Stress X (MPa)

σy — Normal Stress Y (MPa)

τxy — Shear Stress (MPa)

⚙ Mechanical Note: Results are based on standard textbook formulas and ISO/AASHTO references. Always verify critical designs with applicable codes (ISO 898, AASHTO 1993, AISC, Eurocode 3) and a qualified engineer.

How to Use

Enter the values for the patient or scenario you are assessing. Apply van der Waals equation (P + a/V²)(V - b) = RT accounting for intermolecular attractions (a) and finite molecular volume (b). Compare with ideal gas. Calculate compressibility factor Z = PV/nRT. Use the van der waals result to inform your clinical assessment.

Related Calculators

Clausius-Clapeyron

Engineering

Specific Heat

Engineering

Entropy Change

Engineering

Van der Waals Gas Calculator

How to Use

Related Calculators

Frequently Asked Questions

What do van der Waals constants a and b represent?

When does ideal gas law fail significantly?

What is the critical point of a van der Waals gas?