Term: standard reaction quantities
https://doi.org/10.1351/goldbook.S05923

Definition:
Infinitesimal changes in thermodynamic functions with extent of reaction divided by the infinitesimal increase in the extent when all the reactants and products are in their standard states. For the quantity X they should be denoted by Δ r X°, but usually only Δ X° is used. For specific types of reactions the subscript r is replaced by: f for formation, c for combustion, a for atomization and superscript ‡ for activation.

Related Terms:
1) extent of reaction (http://doi.org/10.1351/goldbook.E02283).
2) activation (http://doi.org/10.1351/goldbook.A00093).

Source: Green Book, 2nd ed., p. 52 (https://goldbook.iupac.org/files/pdf/green_book_2ed.pdf)

Citation: 'standard reaction quantities' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.S05923

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