freezing pointfreez·ing point
the temperature at which a liquid freezes or becomes solid: the freezing point of water is 32°F or 0°C
- The temperature at which a liquid of specified composition solidifies under a fixed pressure, usually standard pressure.
- The temperature at any fixed pressure at which the liquid and solid phases of a substance of specified composition are in equilibrium.
The temperature at which a liquid, releasing sufficient heat, becomes a solid. For a given substance, the freezing point of its liquid form is the same as the melting point of its solid form, and depends on such factors as the purity of the substance and the surrounding pressure. The freezing point of water at a pressure of one atmosphere is 0°C (32°F); that of liquid nitrogen is −209.89°C (−345.8°F).
See also state of matter
(plural freezing points)
- In the case of a pure substance, and of a certain small class of mixtures, there is no further fall in temperature until the substance has become completely solid, but, in the case of most mixtures, after the freezing-point has been reached the temperature soon begins to fall again, and as the amount of solid increases the temperature becomes lower and lower.
- In the winter months of November and December the thermometer frequently falls to freezing-point, and in the hottest months the maximum on the Kibyen plateau has been found to be rarely over 85° The population of Bauchi is estimated at about 1,000,000 and is of a very various description.
- The south-eastern corner is crossed by an annual isotherm of 60°, the north-western by one of 50°; and although in the former region sometimes not a day in the year may show an average temperature below freezing-point, at Jefferson City there are occasionally two months of freezing weather, and at Rockport three.
- It consists of two branches AC and BC, which meet in a lowest point C. It will be seen that as we increase the percentage of B from nothing up to that of the mixture C, the freezing-point becomes lower and lower, but that if we further increase the percentage of B in the mixture, the freezing-point rises.
- These freezing-point curves and transformation curves thus divide the diagram into 8 distinct regions, each with its own specific state or constitution of the metal, the molten state for region 1, a mixture of molten metal and of solid austenite for region 2, austenite alone for region 4 and so on.