Title: solvent mole fraction
Long Title: IUPAC Gold Book - solvent mole fraction
DOI: 10.1351/goldbook.15361
Status: current

Definition
Mole or mass fraction of a solvent in a solution containing \(s\) solute constituents (\(i = 1, 2, \ldots, s\)) and \(p\) solvent constituents (\(i = s + 1, s + 2, \ldots, p\)). For a solvent \(\ce{A}\), \[x_{{\rm{v}},{\ce{A}}} = x_{\ce{A}}/\sum \limits_{i=s+1}^{p} x_{i}\] where \[\sum \limits_{i=1}^{p} x_{i} = \sum \limits_{i=1}^{s} x_{i} + \sum \limits_{i=s+1}^{p} x_{i} = 1\] and analogously for \(w_{{\rm{v}},{\ce{A}}}\), where the first and last summations are over all solvent constituents.

Related Terms
- Jänecke coordinates: https://goldbook.iupac.org//terms/view/15373
- Mole: https://goldbook.iupac.org//terms/view/15376
- constituents: https://goldbook.iupac.org//terms/view/16269

Source
- PAC, 2008, 80, 233. 'Glossary of terms related to solubility (IUPAC Recommendations 2008)' on page 266 (https://doi.org/10.1351/pac200880020233)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/15361/html
- json: https://goldbook.iupac.org/terms/view/15361/json
- xml: https://goldbook.iupac.org/terms/view/15361/xml

Citation: Citation: 'solvent mole fraction' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.15361
License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms.
Collection: If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .
Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.
Accessed: 2026-07-25T21:29:10+00:00