Term: refractive index increment
https://doi.org/10.1351/goldbook.R05241

Definition:
The change of the solution refractive index, n, with solute concentration, C, i.e. ∂n/∂C.

Notes:
0) The solute concentration is most frequently expressed in terms of mass concentration, molality or @V06643@. If expressed in terms of mass concentration or molality, the corresponding @R05240@ increments are referred to as specific or @M03969@ @R05240@ increments, respectively.
1) Following use of the full name, the abbreviated name refractive increment may be used.

Related Terms:
1) volume fraction (http://doi.org/10.1351/goldbook.V06643).
2) refractive index (http://doi.org/10.1351/goldbook.R05240).
3) molal (http://doi.org/10.1351/goldbook.M03969).

Source: Purple Book, 1st ed., p. 65 (http://old.iupac.org/publications/books/author/metanomski.html)

Citation: 'refractive index increment' 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.R05241

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