Jäädyttämislämpötila

Jäädyttämislämpötila, also known as freezing point, is the temperature at which a liquid changes into a solid at a given pressure. For most pure substances, this transition occurs at a specific, characteristic temperature. As a substance freezes, its molecules lose kinetic energy and arrange themselves into a more ordered crystalline structure. The reverse process, melting, occurs at the same temperature under the same pressure. This equilibrium between solid and liquid phases at the freezing point is a fundamental physical property.

The freezing point of water is a commonly known example, being 0 degrees Celsius (32 degrees Fahrenheit) at standard atmospheric pressure. However, the freezing point can be influenced by various factors. For instance, impurities dissolved in a liquid generally lower its freezing point. This phenomenon, known as freezing point depression, is utilized in applications like adding salt to icy roads to melt the ice, as the salt lowers the freezing point of water. Pressure also affects the freezing point, though the effect is less pronounced for most substances than temperature or impurities.

Understanding the freezing point is crucial in many scientific and industrial fields, including chemistry, meteorology, and materials science. It helps in identifying substances, controlling chemical reactions, and predicting weather patterns. The precise measurement of freezing points is also an important method for determining the purity of chemical compounds.