Monosodium citrate

Monosodium citrate

Names
Other names sodium dihydrogen 2-hydroxypropane-1,2,3-tricarboxylate
Identifiers
CAS Number	18996-35-5
3D model (JSmol)	Interactive image
ChEBI	CHEBI:53258
ChemSpider	27304
ECHA InfoCard	100.038.834
EC Number	242-734-6
E number	E331i (antioxidants, ...)
PubChem CID	23662352
RTECS number	GE9750000
UNII	68538UP9SE
CompTox Dashboard (EPA)	DTXSID80872904
InChI 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 Key: HWPKGOGLCKPRLZ-UHFFFAOYSA-M 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
SMILES C(C(=O)O)C(CC(=O)O)(C(=O)[O-])O.[Na+]
Properties
Chemical formula	C6H7NaO7
Molar mass	214.105 g·mol−1
Appearance	white powder hygroscopic
Odor	odorless
Melting point	212 °C (414 °F; 485 K)
Solubility in water	soluble
Solubility	negligible in ethanol
Acidity (pKa)	3.50 - 3.80
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

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 an aqueous solution of sodium bicarbonate or carbonate with citric acid.

NaHCO₃ + C₆H₈O₇ → NaC₆H₇O₇ + CO₂ + H₂O

It is highly soluble in water and practically insoluble in ethanol. Monosodium citrate is used as an anticoagulant in donated blood.^[1]

References