Sodium diacetate

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Sodium diacetate
Sodium diacetate
IUPAC name
Sodium diacetate
Other names
Sodium diacetate (anhydrous); Sodium hydrogen acetate; Sodium acid acetate
  • 126-96-5 checkY
3D model (JSmol)
ECHA InfoCard 100.004.378 Edit this at Wikidata
MeSH diacetate sodium diacetate
  • InChI=1S/2C2H4O2.2Na/c2*1-2(3)4;;/h2*1H3,(H,3,4);;/q;;2*+1/p-2
  • O=C(C)O[H-]OC(C)=O.[Na+]
Molar mass 142.086 g·mol−1
Appearance White powder
Odor Acetic acid (vinegar) odor
1 g/mL
Solubility in alcohol Slightly
Solubility in ether Insoluble
Safety data sheet PubChem sodium diacetate LCSS
GHS pictograms GHS05: Corrosive GHS07: Harmful[1]
GHS Signal word Danger
H318, H319[2]
P264, P280, P305+351+338, P310, P337+313[2]
Inhalation hazard Irritant[2]
Eye hazard Irritant[2]
Flash point >150 °C (302 °F)[2]
Lethal dose or concentration (LD, LC):
>2,000 mg/kg (rat, dermal), 5,600 mg/kg (rat, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Sodium diacetate is a compound with formula NaH(C
. It is a salt of acetic acid. It is a colorless solid that is used in seasonings and as an antimicrobial agent.

Preparation and structure[edit]

The salt forms upon half-neutralization of acetic acid followed by evaporation of the solution. It can be viewed as the result of homoassociation, an effect that enhances the acidity of acetic acid in concentrated solution:

2 CH3CO2H + NaOH → Na+[(CH3CO2)2H] + H2O

Also described as the sodium acid salt of acetic acid, it is best described as the sodium salt of the hydrogen-bonded anion (CH3CO2)2H. The O···O distance is about 2.47 angstrom.[3] The species has no significant existence in solution but forms stable crystals.


As a food additive,[4] it has E number E262 and is used to impart a salt and vinegar flavor.

See also[edit]


  1. ^ PubChem. "Sodium diacetate". PubChem. Retrieved 2019-10-24.
  2. ^ a b c d e PubChem. "Sodium diacetate". PubChem. Retrieved 2019-10-24.
  3. ^ Barrow, Michael J.; Currie, Murdoch; Muir, Kenneth W.; Speakman, J. Clare; White, David N, J. "Crystal structures of some acid salts of monobasic acids. XVII. Structure of sodium hydrogen diacetate, redetermined by neutron diffraction" Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry 1975, pp. 15-18. doi:10.1039/P29750000015
  4. ^ Peter J. Taormina "Implications of Salt and Sodium Reduction on Microbial Food Safety" in Critical Reviews in Food Science and Nutrition, 2010, vol. 50, 209-227. doi:10.1080/10408391003626207