: the temperature at which a liquid solidifies; specifically: the temperature at which the liquid and solid states of the substance are in equilibrium at atmospheric pressure :melting point<the freezing point of water is 0° Celsius or 32° Fahrenheit>
Temperature at which a liquid becomes a solid. When the pressure surrounding the liquid is increased, the freezing point is raised. The addition of some solids can lower the freezing point of a liquid, a principle used when salt is applied to melt ice on frozen surfaces. For pure substances, the freezing point is the same as the melting point. In mixtures and certain organic compounds, the early solid formation changes the composition of the remaining liquid, usually steadily lowering its freezing point, a principle that is applied in mixture separation. The freezing point of pure water at standard atmospheric pressure is 32°F (0°C). To change a liquid at its freezing point to a solid at the same temperature, the heat of fusion (seelatent heat) must be removed.