Chapter 3B

3B. Properties of Paraffin Hydrocarbons Back to Main

This page is used, as a reliable estimate of physical properties as required in order to obtain reliable calculations. For single component systems, data are readily available. This table is an example of such data.

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

The boiling point reflects the strengths of the intermolecular forces. A liquid boils when bubbles of its vapor form within the liquid. The molecules of a liquid must overcome their attractive forces in order to separate and form a vapor. The stronger the attractive force the higher the temperature at which the liquid boils.

The freezing point of a substance is identical to its melting point. The two differ only in the temperature direction from which the phase change is approached.

The vapor pressure is the pressure exerted by a vapor in equilibrium with its liquid or solid phase.

The relative density of gas is the molecular weight divided by the molecular weight of air.

Volume =

Critical Conditions are:

Critical temperature () is the highest temperature at which it is possible to convert the gaseous from 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 – Rankine 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 Heat of Vaporization is the enthalpy change (D H), for vaporizing a liquid.

Specific Heat is the heat capacity of 1 g of a substance; the heat required to raise the temperature of 1 g of a substance by 1°C.

To select either SI metric unit or English units click on appropriate tab above the chart.

The SI system has seven base units from which all other units are derived.

Physical Quantity | Name of Unit | Abbreviation
Mass | Kilogram | kg
Length | Meter | m
Time | Second | s
Electric current | Ampere | A
Temperature | Luminous intensity | K
Amount of substance | Mole | mol

Prefixes Used in the SI System

Prefix | Abbreviation | Meaning
Mega- | M |
Kilo- | k |
Deci- | d |
Centi- | c |
Milli | m |

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