The boiling point of a compound is the temperature where the liquid-gas phase change occurs. In more technical terms, it is when a liquid's vapor pressure equals its applied pressure (typically the atmospheric pressure). Boiling points are very sensitive to changes in applied pressure, so all boiling points should be reported along with the measured pressure. A compound's "normal boiling point" refers to its boiling point at a pressure of 760 mmHg. A compound's boiling point is a physical constant just like melting point, and so can be used to support the identification of a compound.
- 6.2B: Step-by-Step Procedures for Boiling Point Determination
- There are a variety of methods by which a sample's boiling point can be determined, including distillation, reflux, and by using a Thiele tube. The most straightforward method uses a Thiele tube, and has the advantage of using less than