Enthalpy: Difference between revisions
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'''Enthalpy''' (<math>H</math>) <ref>[http://www.dwc.knaw.nl/DL/publications/PU00013601.pdf J. P. Dalton "Researches on the Joule-Kelvin effect, especially at low temperatures. I. Calculations for hydrogen", KNAW Proceedings '''11''' pp. 863-873 (1909)]</ref><ref>[http://dx.doi.org/10.1021/ed079p697 Irmgard K. Howard "H Is for Enthalpy, Thanks to Heike Kamerlingh Onnes and Alfred W. Porter", Journal of Chemical Education '''79''' pp. 697-698 (2002)]</ref> is defined as: | '''Enthalpy''' (<math>H</math>) <ref>[http://www.dwc.knaw.nl/DL/publications/PU00013601.pdf J. P. Dalton "Researches on the Joule-Kelvin effect, especially at low temperatures. I. Calculations for hydrogen", KNAW Proceedings '''11''' pp. 863-873 (1909)]</ref><ref>[http://dx.doi.org/10.1021/ed079p697 Irmgard K. Howard "H Is for Enthalpy, Thanks to Heike Kamerlingh Onnes and Alfred W. Porter", Journal of Chemical Education '''79''' pp. 697-698 (2002)]</ref> is defined as: | ||
:<math> | :<math>H:=U+pV</math> | ||
where <math>U</math> is the [[internal energy]], <math>p</math> is the [[pressure]], <math>V</math> is the volume. | where <math>U</math> is the [[internal energy]], <math>p</math> is the [[pressure]], <math>V</math> is the volume. | ||
Latest revision as of 18:50, 20 February 2015
Enthalpy (Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle H} ) [1][2] is defined as:
- Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle H:=U+pV}
where Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle U} is the internal energy, Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle p} is the pressure, Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle V} is the volume. Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle pV} is a conjugate pair. The differential of this function is
- Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \left.dH\right.=dU+pdV+Vdp}
From the Second law of thermodynamics one obtains
- Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \left.dH\right.=TdS -pdV +pdV+Vdp}
thus we arrive at
- Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \left.dH\right.=TdS +Vdp}
For Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle H(S,p)} we have the following total differential
- Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle dH=\left(\frac{\partial H}{\partial S}\right)_p dS + \left(\frac{\partial H}{\partial p}\right)_S dp}
References[edit]
- ↑ J. P. Dalton "Researches on the Joule-Kelvin effect, especially at low temperatures. I. Calculations for hydrogen", KNAW Proceedings 11 pp. 863-873 (1909)
- ↑ Irmgard K. Howard "H Is for Enthalpy, Thanks to Heike Kamerlingh Onnes and Alfred W. Porter", Journal of Chemical Education 79 pp. 697-698 (2002)