Sodium diacetate

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Sodium diacetate
Sodium diacetate
Other names
Sodium hydrogen acetate; Sodium acid acetate
126-96-5 YesY
ChemSpider 29100
Jmol-3D images Image
Molar mass 142.09 g·mol−1
Except where noted otherwise, data is 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, is best described as the sodium salt of the hydrogen-bonded anion (CH3CO2)2H. The O---O distance is about 2.47 Å.[1] The species has no significant existence in solution but forms stable crystals.


As a food additive,[2] it has E number E262 and is used to impart a salt and vinegar flavor.

See also[edit]


  1. ^ 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
  2. ^ 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