Enthalpy: Difference between revisions

From SklogWiki
Jump to navigation Jump to search
mNo edit summary
mNo edit summary
Line 3: Line 3:
:<math>\left.H\right.=U+pV</math>
:<math>\left.H\right.=U+pV</math>


''(-pV)'' is a ''conjugate pair''. The differential of this function is
where <math>U</math>  is the [[internal energy]], <math>p</math> is the [[pressure]], <math>V</math> is the volume and ''(-pV)'' is a ''conjugate pair''. The differential of this function is


:<math>\left.dH\right.=dU+pdV+Vdp</math>
:<math>\left.dH\right.=dU+pdV+Vdp</math>

Revision as of 15:19, 29 January 2008

Definition of the enthalpy, H

Failed to parse (Conversion error. Server ("https://wikimedia.org/api/rest_") reported: "Cannot get mml. Server problem."): {\displaystyle \left.H\right.=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 and (-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

For 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}