Condensaatio

Condensaatio, or condensation, is the process by which a substance changes from a gaseous state to a liquid, or, in chemistry, when two molecules join to form a larger molecule with the concurrent loss of a small molecule such as water. The term derives from Latin condensatio, meaning to press together.

In meteorology and everyday life, condensation occurs when water vapor cools and reaches its dew point, producing clouds, fog, dew, or condensation on surfaces. The rate depends on temperature, pressure, humidity, and the presence of condensation nuclei such as dust or salt particles that provide surfaces for droplets to form.

In industry, condensation is harnessed in distillation, refrigeration, and air conditioning. Controlling condensation requires managing temperature and humidity and often involves condensate drains or traps to remove liquid water from systems. Dew point measurements help prevent moisture problems in buildings and process plants.

In chemistry, condensation reactions join two molecules with the loss of a small molecule (often water) to give a larger product. Examples include esterification, amide formation, and polymerization. These reactions are widely used in biology and materials science, and may be accelerated by catalysts and controlled by reaction conditions.

A related concept in physics is the Bose–Einstein condensate, a state of matter that occurs at very low temperatures when particles occupy the same quantum state.