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The Antoine equation is a class of semi-empirical correlations describing the relation between vapor pressure and temperature for pure substances. The Antoine equation is derived from the Clausius–Clapeyron relation. The equation was presented in 1888 by the French engineer Louis Charles Antoine (1825–1897). [1]
To provide a rough example of how much pressure this is, to melt ice at −7 °C (the temperature many ice skating rinks are set at) would require balancing a small car (mass ~ 1000 kg [19]) on a thimble (area ~ 1 cm 2). This shows that ice skating cannot be simply explained by pressure-caused melting point depression, and in fact the mechanism ...
The Antoine equation [3] [4] is a pragmatic mathematical expression of the relation between the vapor pressure and the temperature of pure liquid or solid substances. It is obtained by curve-fitting and is adapted to the fact that vapor pressure is usually increasing and concave as a function of temperature. The basic form of the equation is:
Examples of modern use of these formulae can additionally be found in NASA's GISS Model-E and Seinfeld and Pandis (2006). The former is an extremely simple Antoine equation, while the latter is a polynomial. [8] In 2018 a new physics-inspired approximation formula was devised and tested by Huang [9] who also reviews other recent attempts.
This is accomplished by solving heat equations in both regions, subject to given boundary and initial conditions. At the interface between the phases (in the classical problem) the temperature is set to the phase change temperature. To close the mathematical system a further equation, the Stefan condition, is required. This is an energy balance ...
The only variable quantity of the ideal gas law independent of density and pressure is temperature. This scaled quantity is known as virtual temperature, and it allows for the use of the dry-air equation of state for moist air. [5] Temperature has an inverse proportionality to density.
The fourth column is the density of the vapor. The fifth column is the heat of vaporization needed to convert one gram of liquid to vapor. Freezing curve of ammonia-water system.
Growth of R-143a concentration in Earth's atmosphere since 2007. [2] HFC-143a measured by the Advanced Global Atmospheric Gases Experiment in the lower atmosphere (troposphere) at stations around the world.