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The boiling point of a substance is the temperature at which it can change state from a liquid to a gas throughout the bulk of the liquid. A liquid may change to a gas at temperatures below the boiling point through the process of evaporation. However, evaporation is a surface phenomenon, in which only molecules located near the gas/liquid surface may evaporate. Boiling on the other hand is a bulk process, so at the boiling point molecules anywhere in the liquid may be vaporized, resulting in the formation of vapor bubbles.
The boiling point corresponds to the temperature at which the vapor pressure of the substance equals the ambient pressure. Thus the boiling point is dependent on the pressure. Usually, boiling points are published with respect to standard pressure (101325 pascal or 1 atm). At higher elevations, where the atmospheric pressure is much lower, the boiling point is also lower. The boiling point increases with increased ambient pressure up to the critical point, where the gas and liquid properties become identical. The boiling point cannot be increased beyond the critical point. Likewise, the boiling point decreases with decreasing ambient pressure until the triple point is reached. The boiling point cannot be reduced below the triple point.
The process of changing from a liquid to a gas requires an amount of heat called the latent heat of vaporization. As heat is added to a liquid at its boiling point, all of this heat goes toward the phase change from liquid to gas, thus the temperature of the substance remains constant even though heat has been added. The word latent, which comes from Latin and means hidden, is used to describe this "disappearing" heat that is added, but doesn't result in an increase in temperature. Since heat is added with no corresponding change in temperature, the heat capacity of the liquid is essentially infinite at the boiling point.
In terms of intermolecular interactions, the boiling point represents the point at which the liquid molecules possess enough heat energyThis article is about the scientific concept. Energy use by humans is discussed in other articles''. Energy generally and qualitatively speaking, is the property (or the quantity of the property) of doing things or supplying power. The expressions energy to overcome the various intermolecular attractions binding the molecules into the liquid (eg. dipole-dipole attraction, instantaneous-dipole induced-dipole attractions, and hydrogen bondsIn chemistry, a hydrogen bond is a type of attractive intermolecular force that exists between two partial electric charges of opposite polarity. Although stronger than most other intermolecular forces, the hydrogen bond is much weaker than both the ionic). Therefore the boiling point is also an indicator of the strength of these attractive forces.
The boiling point of water is 100 °CThe degree Celsius (°C) is a unit of temperature named after the Swedish astronomer Anders Celsius ( 1701 1744), who first proposed it in 1742. The Celsius temperature scale was designed so that the freezing point of water is 0 degrees, and the boiling po (212 °FThis article is about the temperature scale; see also Fahrenheit graphics API. Fahrenheit is a temperature scale named after the German physicist Gabriel Fahrenheit ( 1686 1736), who proposed it in 1724. In this scale, the freezing point of water is 32 de) at standard pressure. On top of Mount Everest the pressure is about 260 mbA millibar is 1/1000th of a bar metric unit for measurement of pressure. It is not an SI unit of measure. The SI unit is the pascal (Pa), with 1 millibar 100 pascals. The millibar unit was introduced by Sir Napier Shaw in 1909, and internationally adopted so the boiling point of water is 69 °CThe degree Celsius (°C) is a unit of temperature named after the Swedish astronomer Anders Celsius ( 1701 1744), who first proposed it in 1742. The Celsius temperature scale was designed so that the freezing point of water is 0 degrees, and the boiling po
See also: Leidenfrost effectThe Leidenfrost effect is the phenomenon in which a liquid in near contact with a mass hotter than the liquid's Leidenfrost point which is higher than its boiling point, produces an insulating vapor layer which keeps it from boiling rapidly. This is most, flash point, boiling delay, critical temperature, triple point
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