Efflorescence

{
  "id": "MLC-T-CHM-003606",
  "term": "Efflorescence",
  "field": "Chemistry",
  "definition": "The process in which a hydrated salt, left in open air, gives up its water of crystallization and develops a dry powdery crust on the crystal surface. It happens when the water vapor pressure of the hydrate exceeds the partial pressure of water vapor in the surrounding air. Washing soda, sodium carbonate decahydrate, effloresces in dry air and crumbles to the monohydrate.",
  "subject": "Chemistry and the Environment",
  "see_also": [
    "crystallization",
    "deliquescence",
    "salt",
    "saturated solution"
  ],
  "references": [
    "PAC, 1990, 62, 2167. 'Glossary of atmospheric chemistry terms (Recommendations 1990)' on page 2186 (https://doi.org/10.1351/pac199062112167)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/efflorescence/"
}