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General
Systematic name	trisodium 2-hydroxypropane-1,2,3-tricarboxylate
Other names	citrosodine; trisodium citrate; citric acid, trisodium salt
Molecular formula	Na3C6H5O7
SMILES	[Na+].[Na+].[Na+]. O=C([O-])CC(O)(CC(=O)[O-])C([O-])=O
Molar mass	258.07 g/mol
Appearance	White crystalline powder
CAS number	[68-04-2] (anhydrous); [6132-04-3] (dihydrate)
Properties
Density and phase	~ 1.7 g/cm³ solid
Solubility in water	72 g/100 ml
Melting point	150 °C
Boiling point	Decomposes
Acidity (p''K''a)	?
Basicity (p''K''b)	?
Structure
Crystal structure	?
Dipole moment	? D
Hazards
MSDS	External MSDS
Main hazards	Irritant
NFPA 704
Flash point	?°C
R/S statement	R: ? S: ?
RTECS number	?
Supplementary data page
Structure and properties	''n'', εr, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Related compounds
Related compounds	calcium citrate, citric acid
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

'Sodium citrate' is the sodium salt of citric acid with the chemical formula of Na₃C₆H₅O₇. Sodium citrate possesses a saline, mildly tart, flavor. For this reason, citrates of certain Alkaline and Alkaline Earth metals (e.g. sodium and calcium citrates) are commonly known as ''sour salt'' (occasionally citric acid is erroneously termed ''sour salt''). Sodium citrate is chiefly used as a food additive, usually for flavor or as a preservative. Sodium citrate is employed as a flavoring agent in certain varieties of club soda.
Sodium citrate is common as an ingredient in lemon-lime and citrus soft drinks such as Ting, contributing to their tart tastes, and can also be found in such energy drinks as Rockstar and Red Bull.
In 1914, the Belgian doctor Albert Hustin and the Argentine physician and researcher Luis Agote successfully used sodium citrate as an anticoagulant in blood transfusions. It continues to be used today in blood collection tubes and for the preservation of blood in blood banks. The citrate ion chelates calcium ions in the blood, disrupting the blood clotting mechanism.
As a conjugate base of a weak acid, citrate can perform as a buffering agent, resisting changes in pH. Sodium citrate is used to control acidity in some substances, such as gelatin desserts. It can be found in the mini milk containers used with coffee machines. The compound is the product of antacids such as Alka-Seltzer when they are dissolved in water.
Research from the British Journal of Sports Medicine (2003) showed that use of sodium citrate (approx. 37 grams) improved running performance over 5 km by 30 seconds. ^[1]
Sodium citrate is used to relieve discomfort in urinary tract infections such as cystitis, to reduce the acidosis seen in distal renal tubular acidosis, and can also be used as an osmotic laxative.

Contents

References

References

1. Oopik, V et al 2003; 37: 485-489