Boiling point The temperature at which

Boiling point The temperature at which the vapor pressure of a liquid is equal to the external pressure, and the liquid changes phase into the vapor state. 

Mid-boiling point the temperature at which approximately 50 percent of a material has distilled under specific conditions. 

Of primary environmental interest are the melting point, boiling point (the temperature at which the vapor pressure equals atmospheric pressure), and related vapor pressure at environmental temperatures. Chapters 1,2, and 3 discuss these properties. Also of interest is the super-cooled liquid vapor pressure, i.e., the vapor pressure which a solid substance would have if it were liquid at environmental temperatures. This vapor pressure, which is shown dashed in the figure, can be obtained by extrapolating the liquid s vapor pressure below the melting point. It cannot be measured directly. For example, naphthalene melts at 80°C, well above environmental temperatures. Its measured solid vapor pressure depends on the stability of the crystal structure of the pure substance, symmetrical molecules... 

Boiling point The temperature at which a liquid changes to a gas. 

Boiling point The temperature at which a liquid boils it is the temperature at which a liquid changes to a gas at atmospheric pressure. 

Normal boiling point the temperature at which the vapor pressure of a liquid is exactly one atmosphere. (16.10) Normal melting point the temperature at which the solid and liquid states have the same vapor pressure under conditions where the total pressure on the system is one atmosphere. (16.10) Normality the number of equivalents of a substance dissolved in a liter of solution. (17.1)... 

Boiling point — The temperature at which a liquid begins to boil. Specifically, it is the temperature at which the vapour pressure of a liquid is equal to the atmospheric or external pressure. The boiling point of crude oils and petroleum products may vary from 30 to 550°C but is of little practical significance in terms of oil spill cleanup. 

Normal boiling point The temperature at which the equilibrium vapor pressure of the liquid equals one atmosphere. 

Boiling point - The temperature at which the liquid and gas phases of a substance are in equilibrium at a specified pressure. The normal boiling point is the boiling point at normal atmospheric pressure (101.325 kPa). 

IBP = Initial Boiling Point, the temperature at which the first drop of solvent is distilled over. 

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