Chapter 3A

3A. Physical Constants Back to Main

Compound is a substance composed of two or more elements united chemically in definite proportions.

Molecular weight is the mass of the collection of atoms represented by the chemical formula for a molecule.

Compressibility Factor () is a measure of the deviation of the actual relation from the ideal-gas equation state (PV = nRT).

Critical temperature () is the highest temperature at which it is possible to convert the gaseous form of a substance to a liquid. The critical temperature increases with an increase in the magnitude of intermolecular force. This value is given in both R – Rankin and K - Kelvin.

Critical pressure () is the pressure at which a gas at it is critical temperature is converted to a liquid state. This value is given in both psia and MPa.

The Eykman (EMR) is a parameter related to the refractive index and molecular weight of a fluid. The values are found from the molecular weight and the specific gravity of the heaviest fraction shown in analysis.

The Acentric Factor (w ) was developed by Pitzer to describe the deviation of a fluid from the simple fluid behavior, or its nonconformity with the corresponding states principle.

Methane |  |
Ethane |  |
Propane |  |
iso –Butane |  |
n – Butane |  |
iso – Pentane |  |
n – Pentane |  |
n – Hexane |  |
n – Heptane |  |
n - Octane |  |
n – Nonane |  |
n – Decane |  |
Nitrogen |  |
Carbon Dioxide |  |
Hydrogen Sulfide |  |
Oxygen |  |
Hydrogen |  |
Water |  |

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