Monosodium citrate, more correctly, sodium dihydrogen citrate (Latin: natrium citricum acidulatum), is an acid salt of citric acid. Disodium citrate and trisodium citrate are also known. It can be prepared by partial neutralisation of citric acid[3] with an aqueous solution of sodium bicarbonate or carbonate. It has a slightly acidic taste.[3]

Monosodium citrate
Names
IUPAC name
Sodium 2-(carboxymethyl)-2,4-dihydroxy-4-oxobutanoate[1]
Other names
sodium dihydrogen 2-hydroxypropane-1,2,3-tricarboxylate
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.038.834 Edit this at Wikidata
EC Number
  • 242-734-6
E number E331i (antioxidants, ...)
RTECS number
  • GE9750000
UNII
  • InChI=1S/C6H8O7.Na/c7-3(8)1-6(13,5(11)12)2-4(9)10;/h13H,1-2H2,(H,7,8)(H,9,10)(H,11,12);/q;+1/p-1 ☒N
    Key: HWPKGOGLCKPRLZ-UHFFFAOYSA-M ☒N
  • InChI=1/C6H8O7.3Na/c7-3(8)1-6(13,5(11)12)2-4(9)10;;;/h13H,1-2H2,(H,7,8)(H,9,10)(H,11,12);;;/q;3*+1/p-3
    Key: HRXKRNGNAMMEHJ-DFZHHIFOAL
  • C(C(=O)O)C(CC(=O)O)(C(=O)[O-])O.[Na+]
Properties
C6H7NaO7
Molar mass 214.105 g·mol−1
Appearance white powder
hygroscopic
Odor odorless
Melting point 212 °C (414 °F; 485 K)
Boiling point 309.6 °C (589.3 °F; 582.8 K)
soluble
Solubility negligible in ethanol
Acidity (pKa) 3.50–3.80
Structure[2]
Monoclinic
P21/a (No. 4)
4
Hazards
Lethal dose or concentration (LD, LC):
5400 mg/kg (mouse, oral) >2000 mg/kg (rat, dermal)
Safety data sheet (SDS) Carl Roth
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)
NaHCO3 + C6H8O7 → NaC6H7O7 + CO2 + H2O
Na2CO3 + 2C6H8O7 → 2NaC6H7O7 + CO2 + H2O

It is highly soluble in water and practically insoluble in ethanol.[3] Monosodium citrate is used as an anticoagulant in donated blood.[4] It is used as an alkalinizing agent to prevent kidney stone disease.[5] The crystals form as nearly perfect cubes.[6]

References

edit
  1. ^ "Sodium dihydrogen citrate".
  2. ^ Glusker, Jenny P.; van der Helm, D.; Love, Warner E.; Dornberg, Marilyn L.; Patterson, A. L. (June 1960). "The State of Ionization of Crystalline Sodium Dihydrogen Citrate1". Journal of the American Chemical Society. 82 (11): 2964–2965. doi:10.1021/ja01496a071. ISSN 0002-7863. Retrieved 22 July 2022.
  3. ^ a b c "Monosodium Citrate - Jungbunzlauer". www.jungbunzlauer.com. Retrieved 17 July 2022.
  4. ^ Clinical Hematology: Theory and Procedures, Mary Louise Turgeon
  5. ^ PubChem. "Monosodium citrate". pubchem.ncbi.nlm.nih.gov. Retrieved 2021-08-02.
  6. ^ Hitchcock, David I. (March 1946). "Sodium Hydrogen Citrates". Journal of the American Chemical Society. 68 (3): 524–525. doi:10.1021/ja01207a507. ISSN 0002-7863. PMID 21015754. Retrieved 22 July 2022.