Liquid Ethylene Density Calculator
Calculate the density of saturated liquid ethylene at any temperature along the boiling curve, from the normal boiling point (−103.77 °C) to the critical point (9.20 °C), using the industry-standard Rackett equation with DIPPR parameters.
°C
Saturated liquid ethylene density via the Rackett equation (DIPPR parameters)
- 1
Temperature (K)
-50 + 273.15 = 223.15 - 2
Reduced temperature (Tᵣ)
223.15 ÷ 282.35 = 0.790331Tᵣ = T / Tᶜ; approaches 1 near the critical point. - 3
Rackett exponent
1 + (1 − 0.790331)^(2/7) = 1.63996 - 4
Molar volume V_L (cm³/mol)
(83.14 × 282.35 ÷ 50.41) × 0.281^1.64 = 58.0772 - 5
Density (kg/m³)
28.054 ÷ 58.0772 × 1000 = 483
How does this calculator work?
Liquid ethylene (C₂H₄) density via the Rackett equation: V_L = (R·Tc/Pc)·Zra^[1+(1−T/Tc)^(2/7)]; ρ = MW/V_L. Valid from −103.77 °C (boiling point, ~568 kg/m³) to 9.20 °C (critical point, ~214 kg/m³). Uses DIPPR parameters: Tc = 282.35 K, Pc = 50.41 bar, Zra = 0.2810. Accuracy ~1–2%.
Formula
How this is calculated
Ethylene (C₂H₄, molar mass 28.054 g/mol) is a light olefin stored and transported as a cryogenic liquid. Its saturated liquid density — the density at the vapour–liquid equilibrium condition for a given temperature — decreases as temperature rises, from about 568 kg/m³ at the normal boiling point (−103.77 °C, 1 atm) to the critical density of 214.2 kg/m³ at the critical point (9.20 °C, 50.4 bar), where liquid and vapour phases become indistinguishable.
This calculator uses the Rackett equation, a widely used correlation for liquid molar volume: V_L = (R·Tc/Pc)·Zra^[1+(1−Tr)^(2/7)], where Tr = T/Tc is the reduced temperature and Zra is the Rackett parameter, a substance-specific fitting constant. For ethylene the DIPPR-recommended values are Tc = 282.35 K, Pc = 50.41 bar, Zra = 0.2810. The molar volume in cm³/mol is converted to density via ρ = MW/V_L × 1000. The Rackett equation is accurate to within approximately 1–2% for most non-associating fluids along the saturation curve.
The calculation is only valid for the saturated liquid phase — that is, on the boiling curve at the pressure corresponding to each temperature. Above 9.20 °C, ethylene cannot exist as a liquid at any pressure below its critical pressure; below −103.77 °C, it would solidify. For liquid density at elevated pressures (compressed liquid), a pressure-corrected equation of state (e.g. Peng–Robinson) would be needed.
Frequently asked questions
At its normal boiling point of −103.77 °C (1 atm), liquid ethylene has a density of approximately 568 kg/m³ (0.568 g/cm³). The Rackett equation gives a value close to this; small deviations from published NIST values are within the ~1–2% accuracy of the correlation.
As temperature rises, molecules gain kinetic energy and push each other further apart, so the liquid expands and its density falls. This continues until the critical point (9.20 °C), where the densities of the liquid and vapour phases converge and the distinction between phases disappears.
The Rackett equation with DIPPR-fitted parameters reproduces experimental saturated liquid density data for ethylene to within about 1–2% across the full liquid range. For more precise work — especially near the critical point where the equation loses accuracy — use the NIST Webbook or a full equation of state such as the IUPAC reference EOS for ethylene.
Also known as
TG we-Calculate Editorial Team. (2026). Liquid Ethylene Density Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/liquid-ethylene-density-calculator
TG we-Calculate Editorial Team. "Liquid Ethylene Density Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/liquid-ethylene-density-calculator.
TG we-Calculate Editorial Team, "Liquid Ethylene Density Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/liquid-ethylene-density-calculator
@misc{wecalculate_liquid_ethylene_density_calculator, title = {Liquid Ethylene Density Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/liquid-ethylene-density-calculator}}, year = {2026}, note = {TG we-Calculate} }
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