Surface excess

{
  "id": "MLC-T-CHM-011639",
  "term": "Surface excess",
  "field": "Chemistry",
  "definition": "A measure of the concentration of a component at an interface, relative to its concentration in the bulk phases. It quantifies the amount of a substance that is adsorbed or desorbed at a surface compared to a hypothetical system where the bulk concentrations extend up to a mathematical dividing surface. This quantity is often expressed in moles per unit area.",
  "subject": "Physical and Biophysical Chemistry",
  "see_also": [
    "Gibbs adsorption",
    "Gibbs surface",
    "dividing surface",
    "interface"
  ],
  "references": [
    "Green Book, 2nd ed., p. 63 (https://goldbook.iupac.org/files/pdf/green_book_2ed.pdf)",
    "PAC, 1986, 58, 967. 'Reporting data on adsorption from solution at the solid/solution interface (Recommendations 1986)' on page 969 (https://doi.org/10.1351/pac198658070967)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/surface-excess/"
}