aesthetics  →
being  →
complexity  →
database  →
enterprise  →
ethics  →
fiction  →
history  →
internet  →
knowledge  →
language  →
licensing  →
linux  →
logic  →
method  →
news  →
perception  →
philosophy  →
policy  →
purpose  →
religion  →
science  →
sociology  →
software  →
truth  →
unix  →
wiki  →
essay  →
feed  →
help  →
system  →
wiki  →
critical  →
discussion  →
forked  →
imported  →
original  →
[ temporary import ]
please note:
- the content below is remote from Wikipedia
- it has been imported raw for GetWiki
{{Other uses}}{{short description|A substance in the gas phase at a temperature lower than its critical point}}{{Use American English|date=July 2019}}File:Nitrogen dioxide gas.jpg|thumb|right|An ampule of nitrogen oxide vapor: brown nitrogen dioxide and colorless dinitrogen tetroxide, in equilibrium ]]In physics, a vapor (American English) or vapour (British English; see spelling differences) is a substance in the gas phase at a temperature lower than its critical temperature,R. H. Petrucci, W. S. Harwood, and F. G. Herring, General Chemistry, Prentice-Hall, 8th ed. 2002, p. 483–86. which means that the vapor can be condensed to a liquid by increasing the pressure on it without reducing the temperature. A vapor is different from an aerosol. An aerosol is a suspension of tiny particles of liquid, solid, or both within a gas.JOURNAL, Cheng, T., Chemical evaluation of electronic cigarettes, Tobacco Control, 23, Supplement 2, 2014, ii11–ii17, 0964-4563, 10.1136/tobaccocontrol-2013-051482, 3995255, 24732157, For example, water has a critical temperature of {{convert| 647|K|C F}}, which is the highest temperature at which liquid water can exist. In the atmosphere at ordinary temperatures, therefore, gaseous water (known as water vapor) will condense into a liquid if its partial pressure is increased sufficiently.A vapor may co-exist with a liquid (or a solid). When this is true, the two phases will be in equilibrium, and the gas-partial pressure will be equal to the equilibrium vapor pressure of the liquid (or solid).


missing image!
- phase-diag2.svg|thumb|300px|right|In a typical-phase diagram, the boundary between gas and the critical point.|The vapor-liquid critical point in a pressure-temperature phase diagramphase diagramVapor refers to a gas phase at a temperature where the same substance can also exist in the liquid or solid state, below the critical temperature of the substance. (For example, water has a critical temperature of 374 Â°C (647 K), which is the highest temperature at which liquid water can exist.) If the vapor is in contact with a liquid or solid phase, the two phases will be in a state of equilibrium. The term gas refers to a compressible fluid phase. Fixed gases are gases for which no liquid or solid can form at the temperature of the gas, such as air at typical ambient temperatures. A liquid or solid does not have to boil to release a vapor.Vapor is responsible for the familiar processes of cloud formation and condensation. It is commonly employed to carry out the physical processes of distillation and headspace extraction from a liquid sample prior to gas chromatography.The constituent molecules of a vapor possess vibrational, rotational, and translational motion. These motions are considered in the kinetic theory of gases.

Vapor pressure

(File:Binary Boiling Point Diagram new.svg|left|thumb|Liquid–vapor equilibrium)File:Vapor being used in a cloud chamber.jpg
The vapor pressure is the equilibrium pressure from a liquid or a solid at a specific temperature. The equilibrium vapor pressure of a liquid or solid is not affected by the amount of contact with the liquid or solid interface.The normal boiling point of a liquid is the temperature at which the vapor pressure is equal to normal atmospheric pressure.For two-phase systems (e.g., two liquid phases), the vapor pressure of the individual phases are equal. In the absence of stronger inter-species attractions between like-like or like-unlike molecules, the vapor pressure follows Raoult's law, which states that the partial pressure of each component is the product of the vapor pressure of the pure component and its mole fraction in the mixture. The total vapor pressure is the sum of the component partial pressures.Thomas Engel and Philip Reid, Physical Chemistry, Pearson Benjamin-Cummings, 2006, p.194


(File:Crepuscular Rays Beam through the Mist Blown from Takkakaw Falls.jpg|thumb|Water vapor is responsible for humidity)

Measuring vapor

Since it is in the gas phase, the amount of vapor present is quantified by the partial pressure of the gas. Also, vapors obey the barometric formula in a gravitational field, just as conventional atmospheric gases do.

See also

  • {{annotated link|Dilution (equation)}}
  • {{annotated link|Evaporation}}
  • {{annotated link|Henry's law}}
  • {{annotated link|Contrail|aka=Vapor trail}}
  • {{annotated link|Vaporizer (disambiguation)}}


{{Reflist}}{{State of matter}}{{Authority control}}

- content above as imported from Wikipedia
- "vapor" does not exist on GetWiki (yet)
- time: 4:03pm EDT - Sat, Aug 24 2019
[ this remote article is provided by Wikipedia ]
LATEST EDITS [ see all ]
Eastern Philosophy
History of Philosophy
M.R.M. Parrott