|Systematic IUPAC name
Hot ice (Sodium acetate trihydrate)
|RTECS number||AJ4300010 (anhydrous)
|Molar mass||82.03 g·mol−1|
|Appearance||White deliquescent powder|
|Density||1.528 g/cm3 (20 °C, anhydrous)
1.45 g/cm3 (20 °C, trihydrate)
|Melting point||324 °C (615 °F; 597 K)
58 °C (136 °F; 331 K)
|Boiling point||881.4 °C (1,618.5 °F; 1,154.5 K)
122 °C (252 °F; 395 K)
119 g/100 mL (0 °C)
123.3 g/100 mL (20 °C)
125.5 g/100 mL (30 °C)
137.2 g/100 mL (60 °C)
162.9 g/100 mL (100 °C)
32.9 g/100 mL (-10 °C)
36.2 g/100 mL (0 °C)
46.4 g/100 mL (20 °C)
82 g/100 mL (50 °C)
|Solubility||Soluble in alcohol, hydrazine, SO2|
|Solubility in methanol||16 g/100 g (15 °C)
16.55 g/100 g (67.7 °C)
|Solubility in ethanol||Trihydrate:
5.3 g/100 mL
|Solubility in acetone||0.5 g/kg (15 °C)|
|Acidity (pKa)||24 (20 °C)
4.76 in CH3COOH
Refractive index (nD)
|100.83 J/mol·K (anhydrous)
229 J/mol·K (trihydrate)
|138.1 J/mol·K (anhydrous)
262 J/mol·K (trihydrate)
Std enthalpy of
|-709.32 kJ/mol (anhydrous)
-1604 kJ/mol (trihydrate)
Gibbs free energy (ΔfG˚)
|-607.7 kJ/mol (anhydrous)|
|Flash point||>250 °C (482 °F; 523 K) |
|600 °C (1,112 °F; 873 K)|
LD50 (Median lethal dose)
|3530 mg/kg (oral, rat)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is: / ?)(|
Sodium acetate is used in the textile industry to neutralize sulfuric acid waste streams and also as a photoresist while using aniline dyes. It is also a pickling agent in chrome tanning and helps to impede vulcanization of chloroprene in synthetic rubber production. In processing cotton for disposable cotton pads, sodium acetate is used to eliminate the buildup of static electricity.
Sodium acetate is used to mitigate water damage to concrete by acting as a concrete sealant, while also being environmentally benign and cheaper than the commonly-used epoxy alternative for sealing concrete against water permeation.
Sodium acetate may be added to food as a seasoning, sometimes in the form of sodium diacetate, a one-to-one complex of sodium acetate and acetic acid, given the E-number E262. It is often used to give potato chips a salt and vinegar flavor.
As the conjugate base of acetic acid, a solution of sodium acetate and acetic acid can act as a buffer to keep a relatively constant pH level. This is useful especially in biochemical applications where reactions are pH-dependent in a mildly acidic range (pH 4-6).
Sodium acetate is also used in heating pads, hand warmers, and hot ice. Sodium acetate trihydrate crystals freeze at 137.12 °F/58.4 °C, (to 136.4 °F/58 °C) dissolving in their water of crystallization. When they are heated past the melting point and subsequently allowed to cool, the aqueous solution becomes supersaturated. This solution is capable of cooling to room temperature without forming crystals. By pressing on a metal disc within the heating pad, a nucleation center is formed, causing the solution to crystallize back into solid sodium acetate trihydrate. The bond-forming process of crystallization is exothermic. The latent heat of fusion is about 264–289 kJ/kg. Unlike some types of heat packs, such as those dependent upon irreversible chemical reactions, a sodium acetate heat pack can be easily reused by immersing the pack in boiling water for a few minutes, until the crystals are completely dissolved, and allowing the pack to slowly cool to room temperature.
For laboratory use, sodium acetate is inexpensive and usually purchased instead of being synthesized. It is sometimes produced in a laboratory experiment by the reaction of variable concentration acetic acid, commonly known in its 5–8% solution as vinegar, with sodium carbonate ("washing soda"), sodium bicarbonate ("baking soda"), or sodium hydroxide ("lye"). Any of these reactions produce sodium acetate and water. When a sodium and carbonate ion-containing compound is used as the reactant, the carbonate anion is displaced from sodium bicarbonate or carbonate, as is the monatomic hydrogen from the hydroxide in acetic acid, forming the intermediate carbonic acid. Carbonic acid readily decomposes under normal conditions into gaseous carbon dioxide and water. This is the reaction taking place in the well-known "volcano" that occurs when the household products, baking soda and vinegar, are combined.
- CH3COOH + NaHCO3 → CH3COONa + H2CO
3 → CO
2 + H
- CH3COOH + NaOH → CH3COONa + H2O
Caesium salts catalyze this reaction.
- Seidell, Atherton; Linke, William F. (1952). Solubilities of Inorganic and Organic Compounds. Van Nostrand.
- Sigma-Aldrich Co., Sodium acetate. Retrieved on 2014-06-07.
- Acetic acid, sodium salt in Linstrom, P.J.; Mallard, W.G. (eds.) NIST Chemistry WebBook, NIST Standard Reference Database Number 69. National Institute of Standards and Technology, Gaithersburg MD. http://webbook.nist.gov (retrieved 2014-05-25)
- Acetic acid, sodium salt, hydrate (1:1:3) in Linstrom, P.J.; Mallard, W.G. (eds.) NIST Chemistry WebBook, NIST Standard Reference Database Number 69. National Institute of Standards and Technology, Gaithersburg MD. http://webbook.nist.gov (retrieved 2014-05-25)
- Clayden, Jonathan; Greeves, Nick; Warren, Stuart; Wothers, Peter (2001). Organic Chemistry (1st ed.). Oxford University Press. ISBN 978-0-19-850346-0.
- "Potato Chip Flavoring Boosts Longevity Of Concrete". Science Daily. 8 August 2007.
- Jungbunzlauer - General Information
- [Courty JM, Kierlik E, Les chaufferettes chimiques, Pour la Science, décembre 2008, p 108-110]
- Ibrahim Dincer and Marc A. Rosen. Thermal Energy Storage: Systems and Applications, page 155
- "Crystallization of Supersaturated Sodium Acetate". Journal of Chemical Education.
- Fake latent heat and supersaturation
- "How do sodium acetate heat pads work?". HowStuffWorks. Retrieved 2007-09-03.
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