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Vaporization (or vapo(u)risation) of an element or compound is a phase transition from the liquid phase to vapor. [1] There are two types of vaporization: evaporation and boiling . Evaporation is a surface phenomenon , whereas boiling is a bulk phenomenon (a phenomenon in which the whole object or substance is involved in the process).
Evaporation is an essential part of the water cycle. The sun (solar energy) drives evaporation of water from oceans, lakes, moisture in the soil, and other sources of water. In hydrology, evaporation and transpiration (which involves evaporation within plant stomata) are collectively termed evapotranspiration. Evaporation of water occurs when ...
Water vapor, water vapour or aqueous vapor is the gaseous phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Water vapor is transparent, like most constituents of the atmosphere. [1]
According to the American Meteorological Society Glossary of Meteorology, saturation vapor pressure properly refers to the equilibrium vapor pressure of water above a flat surface of liquid water or solid ice, and is a function only of temperature and whether the condensed phase is liquid or solid. [17]
The boiling point is the temperature at which there is equilibrium between liquid and gas phases. At the boiling point, the number of gas molecules condensing to liquid equals the number of liquid molecules evaporating to gas. Adding a solute dilutes the concentration of the liquid molecules and reduces the rate of evaporation.
If the process involves an infinitesimal amount of water, , and an infinitesimal difference in temperature , the heat absorbed is =, and the corresponding work is = (″ ′), where ″ ′ is the difference between the volumes of in the liquid phase and vapor phases.
The boiling point of water is the temperature at which the saturated vapor pressure equals the ambient pressure. Water supercooled below its normal freezing point has a higher vapor pressure than that of ice at the same temperature and is, thus, unstable. Calculations of the (saturation) vapor pressure of water are commonly used in meteorology.
Colloids are formed by phase separation, though not all phase separations forms colloids - for example oil and water can form separated layers under gravity rather than remaining as microscopic droplets in suspension. A common form of spontaneous phase separation is termed spinodal decomposition; it is described by the Cahn–Hilliard equation.