Sodium diacetate

Sodium diacetate is a compound with formula NaH(C
₂H
₃O
₂)
₂. It is a salt of acetic acid. It is a colorless solid that is used in seasonings and as an antimicrobial agent.

Sodium diacetate

Sodium diacetate
Names
IUPAC name Sodium diacetate
Other names Sodium diacetate (anhydrous); Sodium hydrogen acetate; Sodium acid acetate
Identifiers
CAS Number	126-96-5 Y
3D model (JSmol)	Interactive image
ChemSpider	29100
ECHA InfoCard	100.004.378
MeSH	diacetate sodium diacetate
PubChem CID	22646212
UNII	26WJH3CS0B Y
CompTox Dashboard (EPA)	DTXSID3034909
InChI InChI=1S/2C2H4O2.2Na/c2*1-2(3)4;;/h2*1H3,(H,3,4);;/q;;2*+1/p-2 Key: OPGYRRGJRBEUFK-UHFFFAOYSA-L
SMILES O=C(C)O[H-]OC(C)=O.[Na+]
Properties
Chemical formula	C4H7NaO4
Molar mass	142.086 g·mol−1
Appearance	White powder
Odor	Acetic acid (vinegar) odor
Solubility in water	1 g/mL
Solubility in alcohol	Slightly
Solubility in ether	Insoluble
Hazards
Occupational safety and health (OHS/OSH):
Inhalation hazards	Irritant[1]
Eye hazards	Irritant[1]
GHS labelling:[1]
Pictograms
Signal word	Danger
Hazard statements	H318, H319
Precautionary statements	P264, P280, P305+P351+P338, P310, P337+P313
Flash point	>150 °C (302 °F)[1]
Lethal dose or concentration (LD, LC):
LD50 (median dose)	>2,000 mg/kg (rat, dermal), 5,600 mg/kg (rat, oral)
Safety data sheet (SDS)	PubChem sodium diacetate LCSS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Preparation and structure

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.^[2] The species has no significant existence in solution but forms stable crystals.

Applications

As a food additive,^[3] it has E number E262 and is used to impart a salt and vinegar flavor.

See also

• Sodium acetate