Liquids - Freezing and Melting Points

For pure compounds the following definitions can be given:

• Melting point - the temperature at which a solid turns into a liquid
• Freezing point - the temperature at which a liquid turns into a solid
  
• The melting and freezing point changes with pressure,  but normally they are given at 1 atm.
• A pure substance has the same freezing and melting points (in practice a small difference between these quantities can be observed).
• For mixtures of compounds (as petroleum), there are ranges of melting and freezing points versus percent of the mixture melted or frozen.
• For a mixture, the initial melting point is close to the melting point of the lightest compound in the mixture, while the initial freezing point is close to the freezing point (or melting point) of the heaviest compound in the mixture.
• Since the melting point increases with molecular weight, for petroleum mixtures the initial freezing point is greater than the initial melting point.

Freezing and melting points of some common liquids at 1 atm:

See also Physical data for hydrocarbons, Melting points of hydrocarbons, alcohols and acids, Physical data for alcohols and carboxylic acids, Physical data for organic sulfur compounds, Physical data for organic nitrogen compounds and Melting and Boiling Point, Density and Solubility in Water for Inorganic Compounds

T_C = T_K - 273.16   (°C)

T_F = T_C * 1.8 + 32  (°F)

• Temperature Converter