Jump to content

Draft:Thermodynamic conventions

From Wikipedia, the free encyclopedia

Conventions, as an agreed way of doing things, appear throughout science, but they play a special role.[1] in thermodynamics where there is a general need to measure properties relatively rather than absolutely. For example, electrode potentials cannot be measured independently, only in couples as differences between so-called redox ‘half reactions’; so a convention is adopted which sets the value of the standard hydrogen electrode E0 = 0 V exactly, thus allowing all other electrode potentials to be quantified relative to that agreed standard. Examples of other thermodynamic conventions are[2][3][4][5][6]:

  • Definition of the sign given to work done by a system
  • Definition as zero the enthalpy (heat content) of substances

Many such conventional standards are defined by scientific authorities like the International Union of Pure and Applied Chemistry, Green book[7][8] as being the best practice for all scientists to follow. Most thermodynamic conventions establish a reference which is the given conventional property value for a particular substance under specified conditions of pressure and temperature. With these cases, the choice is usually straightforward and the selected references rarely change. Sometimes, however, the convention needs to be more complicated, which makes consensus more difficult to achieve. Three especially controversial instances have been described[1]. One of these concerns the definition of pH[9] so it has implications for topical debates concerning the rates of ocean acidification[10], CO2 uptake by carbonate precipitation[11], and hydrogen production by water electrolysis[12]

References

[edit]
  1. ^ a b Filella, M.; May, E.F.; May, P.M. (2025). "Thermodynamic conventions". International Journal of Thermophysics. 46 (5) 61. Bibcode:2025IJT....46...61F. doi:10.1007/s10765-025-03533-5.
  2. ^ Glasstone, S. (1947). Thermodynamics for Chemists. New York, U.S.A.: D. Van Nostrand Co. Inc. ISBN 9781406773224. {{cite book}}: ISBN / Date incompatibility (help)
  3. ^ Prausnitz, J.M.; Lichtenthaler, R.N.; de Azevedo, E.G. (1999). Molecular Thermodynamics of Fluid-Phase Equilibria (3rd ed.). Engelwood Cliffs, U.S.A.: Prentice Hall Inc. pp. 222–225.
  4. ^ Bridgman, P.W. (1941). The Nature of Thermodynamics. Cambridge, Mass., U.S.A.: Harvard Univ. Press.
  5. ^ Levine, I.N. (2002). Physical Chemistry (6th ed.). N.Y., U.S.A.: McGraw-Hill.
  6. ^ Anderson, G.H. (2005). Thermodynamics of Natural Systems (2nd ed.). Cambridge, U.K.: Cambridge University Press.
  7. ^ Cohen, E.R.; Cvitas, T.; Frey, J.G.; Holmström, B.; Kuchitsu, K.; Marquardt, R.; Mills, I.; Pavese, F.; Quack, M.; et al. (et al.) (2008). Quantities, Units and Symbols in Physical Chemistry, IUPAC Green Book (2nd Printing, 3rd ed.). Cambridge: IUPAC & RSC Publishing.
  8. ^ Brett, Christopher M A; Frey, Jeremy G; Hinde, Robert; Kuroda, Yutaka; Marquardt, Roberto; Pavese, Franco; Quack, Martin; Stohner, Jürgen; Thor, Anders J, eds. (2023). Quantities, Units and Symbols in Physical Chemistry (Abridged Version, 4th ed.). Royal Society of Chemistry. ISBN 978-1-83916-150-6.
  9. ^ May, P.M.; May, E.F. (2024). "Ion Trios: Cause of Ion Specific Interactions in Aqueous Solutions and Path to a Better pH Definition". ACS Omega. 9 (46): 46373–46386. doi:10.1021/acsomega.4c07525. PMC 11579776. PMID 39583676.
  10. ^ Camaselle, S.; Velo, A.; Doval, M. D.; Broullón, D.; Pérez, F. F. (2024). "Long-term trends of pH, alkalinity, and hydrogen ion concentration in an upwelling-dominated coastal ecosystem: Ría de Vigo, NW Spain". Sci Rep. 14 (1) 17929. Bibcode:2024NatSR..1417929C. doi:10.1038/s41598-024-68694-z. PMC 11297135. PMID 39095574.
  11. ^ Poulain, A.; Besselink, R.; Fernandez-Martínez, A.; Kellermeier, M.; Van Driessche, A.E.S. (2024). "A high-throughput approach for assessing antiscaling performance during mineral precipitation from seawater and hard water". npj Clean Water. 7 30. Bibcode:2024npjCW...7...30P. doi:10.1038/s41545-024-00324-7.
  12. ^ Li, T.; Wang, B.; Cao, Y.; Liu, Z.; Wang, S.; Zhang, Q.; Sun, J.; Zhou, G. (2024). "Energy-saving hydrogen production by seawater electrolysis coupling tip-enhanced electric field promoted electrocatalytic sulfion oxidation". Nature Communications. 15 (1) 6173. Bibcode:2024NatCo..15.6173L. doi:10.1038/s41467-024-49931-5. PMC 11263359. PMID 39039041.