Liquid Ethylene Density Calculator
Calculate density from measured mass and volume, and estimate the expected density of liquid ethylene from temperature and pressure.
Measured density
Use a measured mass and occupied volume. Both fields are required.
Temperature and pressure lookup
The estimate uses a temperature-dependent saturated-liquid baseline plus a modest compressed-liquid pressure correction.
Live results
Density detail
| Method | Density (kg/m³) | Density (g/cm³) | Density (lb/ft³) | Basis |
|---|---|---|---|---|
| Measured mass ÷ volume | 568.18 | 0.56818 | 35.47 | 500 kg / 0.88 m³ |
| Temperature-pressure estimate | 586.39 | 0.58639 | 36.61 | – 110.0 °C at 5.000 bar |
How to use the liquid ethylene density calculator
What this calculator does
This tool provides two complementary density results for liquid ethylene. The Measured density result is an exact identity based on the mass and volume you enter. The Estimated liquid ethylene density result is a property estimate based on temperature and pressure. It is useful for quick checks, laboratory planning, vessel inventory calculations, and comparing a measured sample with an expected liquid-state value. It does not determine purity, certify a custody-transfer quantity, or replace a full thermodynamic equation of state for safety-critical design.
When to use it
Use the calculator when you need to convert a known mass and volume into density, check whether a cryogenic sample is near an expected ethylene density, compare a tank measurement with a temperature-pressure estimate, or prepare a compact spreadsheet record for a calculation. The NIST Chemistry WebBook ethylene data provides authoritative thermophysical context for the substance and its critical properties.
How to calculate
- The calculator opens with a ready-to-use demonstration: 500 kg, 0.88 m³, – 110 °C, and 5 bar. Results and a validated Excel workbook are available immediately.
- Replace Mass and Volume with your measured values. Select the matching units; changing a unit converts the current value rather than merely relabeling it.
- Enter the liquid Temperature and absolute Pressure. Keep temperature within – 123 to – 103.7 °C, where this compact lookup model is supported.
- Read the two density results, then use Difference and Relative difference to compare measurement with the property estimate.
- Select Download Excel to create a fresh workbook from the current validated inputs. Reset clears the demonstration values and results; Excel export remains disabled until a complete valid state is entered again.
Input guide
Mass is required and accepts a positive decimal in kilograms, grams, pounds, or the selected unit. A realistic example is 500 kg. Increasing mass while volume stays fixed increases measured density proportionally. Do not enter a container's gross mass unless tare mass has been removed.
Mass unit selects kg, g, or lb and converts the live value. The parser uses a decimal point and rejects scientific notation, mixed symbols, and ambiguous decimal-comma input.
Volume is required and accepts a positive decimal in cubic meters, liters, cubic feet, or U.S. gallons. The startup value is 0.88 m³. Increasing volume while mass stays fixed lowers measured density. Use the occupied liquid volume, not nominal tank capacity.
Volume unit converts the current volume between m³, L, ft³, and U.S. gal. A common mistake is entering liters while leaving m³ selected, which changes the result by a factor of 1,000.
Temperature is required. Enter – 123 to – 103.7 °C, the equivalent kelvin value, or the equivalent Fahrenheit value. The example is – 110 °C. Warmer liquid is generally less dense. Temperatures outside the model range are rejected rather than extrapolated.
Temperature unit switches among °C, K, and °F and converts the current value. Negative Celsius values are normal for liquid ethylene; do not confuse – 110 °C with – 110 K.
Pressure is required and means absolute pressure. Enter a positive value up to 500 bar or its equivalent in kPa, MPa, or psi. The example is 5 bar. Higher pressure gives a small compressed-liquid density increase. Gauge pressure should be converted to absolute pressure before entry.
Pressure unit converts the current pressure. One bar is close to atmospheric pressure but is not exactly one atmosphere; the NIST pressure-unit guidance explains common pressure units and SI practice.
Output guide
Measured density is mass divided by volume after conversion to kilograms and cubic meters. It is displayed in kg/m³ and repeated in the table as g/cm³ and lb/ft³. A zero or negative value is not allowed because both source quantities must be positive.
Estimated liquid ethylene density is the temperature-dependent liquid baseline adjusted for pressure above the calculated saturation pressure. It is an estimate rather than an exact identity. Lower temperatures usually produce higher values.
Difference equals measured density minus estimated density. A negative result means the measured value is lower. Relative difference expresses that difference as a percentage of the estimated density. A value near zero indicates close agreement, but it does not by itself prove sample purity or measurement quality.
Saturation pressure is the approximate vapor pressure at the selected temperature. State check confirms whether the temperature is inside the supported liquid-data range and whether the entered pressure is at least the estimated saturation pressure. The summary pills repeat the two density values and phase status for rapid scanning. The Density detail table shows each method in kg/m³, g/cm³, and lb/ft³ along with its calculation basis.
Worked example
With the startup values, the measured calculation is:
The display rounds this to 568.18 kg/m³. At – 110 °C, the model estimates a saturated-liquid baseline near 586.20 kg/m³ and a saturation pressure of about 0.689 bar. Raising the pressure to 5 bar adds a small compressed-liquid correction, giving 586.39 kg/m³. The measured result is therefore 18.21 kg/m³ lower, or about – 3.11% relative to the estimate.
How the model works
The direct calculation uses the standard density identity:
where ρ is density, m is mass, and V is volume. The lookup path uses a monotonic interpolation through representative liquid-density values from – 123 to – 103.7 °C, then applies a small pressure correction above the estimated saturation pressure. The vapor-pressure relation is based on an Antoine-style correlation over this cryogenic range. For high-accuracy process design, consult a full equation of state such as the thermophysical-property systems described by the NIST REFPROP program.
Interpreting differences
A disagreement between measured and estimated density may come from temperature gradients, pressure uncertainty, volume calibration, trapped vapor, dissolved contaminants, incorrect tare subtraction, or use of gauge rather than absolute pressure. Compare the magnitude with the uncertainty of each instrument before drawing conclusions. The calculator preserves full numeric precision in the downloadable workbook while rounding the page display for readability.
Useful physical context
Ethylene, also called ethene, has the formula C₂H₄. At approximately atmospheric pressure it boils near – 103.7 °C and melts near – 169.2 °C. Its critical point is above the range used by this compact calculator. The PubChem ethylene record provides additional identity, hazard, and physical-property information.