| Autor: |
Malloum A; Department of Physics, Faculty of Science, The University of Ngaoundere, 454 Ngaoundere, Cameroon., Fifen JJ; Department of Physics, Faculty of Science, The University of Ngaoundere, 454 Ngaoundere, Cameroon., Dhaouadi Z; Laboratoire de Spectroscopie Atomique et Moléculaire, Faculté des Sciences, Université de Tunis El Manar, Campus Universitaire, 1060 Tunis, Tunisia., Engo SG; Department of Physics, Faculty of Science, The University of Ngaoundere, 454 Ngaoundere, Cameroon., Jaidane NE; Laboratoire de Spectroscopie Atomique et Moléculaire, Faculté des Sciences, Université de Tunis El Manar, Campus Universitaire, 1060 Tunis, Tunisia. |
| Abstrakt: |
We provide in this work, the absolute solvation enthalpies and the absolute solvation free energies of the proton in ammonia explicitly versus temperature. As a result, the absolute solvation free energy of the proton remains quite constant for temperatures below 200 K. Above this temperature, it increases as a linear function of the temperature: ΔG am (H + ,T)=-1265.832+0.210 T. This indicates that a temperature change of 100 K would induce a solvation free energy change of 21 kJ mol -1 . Thus, ignoring this free energy change would lead to a bad description of hydrogen bonds and an unacceptable error higher than 3.7 pK a units. However, the absolute solvation enthalpy of the proton in ammonia is not significantly affected by a temperature change and, the room temperature value is -1217 kJ mol -1 . The change of the solvation enthalpy is only within 3 kJ mol -1 for a temperature change up to 200 K. |
