Dear Meysam, In principle they are different quantities. Generally enthalpy (H) is related to the internal energy (E) as H=E+PV (P=pressure V=volume)....so change in enthalpy upon adsorption of a molecule (enthalpy of adsorption) is given by
dH=dE+PdV+VdP where dE is the adsorption energy for your case (and is -ve if the molecule binds). Now if you consider your system to be the surface with molecule adsorbed on it, then for a given coverage, the volume & pressure is constant.....so in that case dH=-dE, i.e. the enthalpy of adsorption is -(adsorption energy) Prasenjit On 15 October 2010 14:18, meysam pazoki <m_pazoki at physics.sharif.edu> wrote: > Dear mohnish and Prasenjit > > Thanks? for your good answers ,I have another question :"Is enthalpy of > adsorbtion equals to energy of adsorbtion?" > I want to calculate enthalpy of adsorbtion and your answers are about energy > of adsorbtion. > > Regards > Meysam Pazoki > SUT > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- PRASENJIT GHOSH, Assistant Professor, IISER Pune, First floor, Central Tower, Sai Trinity Building Garware Circle, Sutarwadi, Pashan Pune, Maharashtra 411021, India Phone: +91 (20) 2590 8203 Fax: +91 (20) 2589 9790
