Absolute activity

{
  "id": "MLC-T-CHM-000047",
  "term": "Absolute activity",
  "field": "Chemistry",
  "definition": "The exponential of a substance's chemical potential divided by the product of the gas constant and the thermodynamic temperature, written lambda = exp(mu/RT). It is a dimensionless measure of how strongly the substance tends to leave its phase. The relative activity used in equilibrium constants is the ratio of the absolute activity to its value in the chosen standard state, so it equals one in that state.",
  "subject": "Physical and Biophysical Chemistry",
  "see_also": [
    "chemical potential",
    "gas constant",
    "thermodynamic temperature"
  ],
  "references": [
    "Green Book, 2nd ed., p. 40 (https://goldbook.iupac.org/files/pdf/green_book_2ed.pdf)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/absolute-activity/"
}