Soap curd

{
  "id": "MLC-T-CHM-010963",
  "term": "Soap curd",
  "field": "Chemistry",
  "definition": "A precipitate formed when soap, an alkali metal salt of a fatty acid, reacts with hard water ions such as calcium or magnesium. These multivalent metal ions form insoluble salts with the fatty acids, which appear as a solid, often flaky, residue. This phenomenon reduces the effectiveness of soap as a cleaning agent.",
  "subject": "Physical and Biophysical Chemistry",
  "see_also": [
    "gel",
    "mesomorphic phase",
    "saturated solution",
    "soap"
  ],
  "references": [
    "PAC, 1972, 31, 577. 'Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry' on page 613 (https://doi.org/10.1351/pac197231040577)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/soap-curd/"
}