05144 IUPAC Gold Book - rate of change of a quantity 10.1351/goldbook.R05144 R05144 current 1 The time derivative \(\frac{\rm{d}Q}{\rm{d}t}\) of the value of the quantity. The differential quotient may also be called derivative (or instantaneous) rate of change. Examples are: rate of change of mass, \(\frac{\rm{d}m}{\rm{d}t}\); rate of change of amount of substance, \(\frac{\rm{d}n}{\rm{d}t}\). amount of substance https://goldbook.iupac.org//terms/view/A00297 PAC, 1992, 64, 1569. 'Quantities and units for metabolic processes as a function of time (IUPAC Recommendations 1992)' on page 1572 (https://doi.org/10.1351/pac199264101569) https://goldbook.iupac.org/terms/view/R05144/html https://goldbook.iupac.org/terms/view/R05144/json https://goldbook.iupac.org/terms/view/R05144/plain Citation: 'rate of change of a quantity' 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.R05144 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. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . 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. 2026-04-19T04:11:47+00:00