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