{"term":{"id":"15373","title":"Jänecke coordinates","longtitle":"IUPAC Gold Book - Jänecke coordinates","doi":"10.1351\/goldbook.15373","code":"15373","status":"current","synonym":"<em>synonym<\/em>: solute mole (or mass) fraction coordinates","definitions":[{"id":1,"text":"Coordinates used mainly in representation of multicomponent phase diagrams that distinguish solutes and a single solvent. The mole or mass fractions of the \\(s\\) solutes are chosen as the primary composition variables and the mole or mass fraction of solvent as a secondary variable, so that the solute amount (mass) fractions may be represented, for example, in ternary and quaternary systems, as linear (ternary) or planar triangular or square planar (quaternary) diagrams, with the solvent amount or mass fraction along an axis perpendicular to the chosen diagram of solute variables. Quantitatively, \\[x_{{\\rm{s}},{\\ce{B}}} = x_{\\ce{B}}\/\\sum \\limits_{i=1}^{s}x_{i}\\] where the summation is over the \\(s\\) solute substances. Note that \\(\\sum \\limits_{i=1}^{s}x_{{\\rm{s}},{\\ce{B}}} = 1\\).","notes":{"1":"The mole fraction of solvent component \\(\\ce{A}\\) in a mixture containing \\(p - s\\) solvents (total species \\(p\\)) is replaced by a special case of the solvent mole fraction \\(x_{{\\rm{s}},{\\ce{A}}} = x_{\\ce{A}}\/\\sum \\limits_{i=s+1}^{p}x_{i}\\), which becomes infinite for pure solvent.","2":"This quantity can be scaled to a finite value by adding an arbitrary constant to the denominator."},"links":[{"term":"mole","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/15376"},{"term":"phase diagrams","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/15346"},{"term":"solvent mole fraction","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/15361"},{"term":"ternary","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/15366"}],"sources":["PAC, 2008, 80, 233. 'Glossary of terms related to solubility (IUPAC Recommendations 2008)' on page 251 (https:\/\/doi.org\/10.1351\/pac200880020233)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/15373\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/15373\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/15373\/plain"},"citation":"Citation: 'Jänecke coordinates' 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.15373","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":"2026-07-27T14:04:50+00:00"}}