Sodium acetate, NaCH3COO, also abbreviated NaOAc, is the sodium salt of acetic acid. It’s also the primary flavoring in salt and vinegar potato chips. This Instructable will show how to make sodium acetate using common household ingredients. This colorless deliquescent salt has a wide range of uses.
Sodium Acetate Anhydrous is the anhydrous, sodium salt form of acetic acid. Sodium acetate anhydrous disassociates in water to form sodium ions (Na+) and acetate ions. Sodium is the principal cation of the extracellular fluid and plays a large part in fluid and electrolyte replacement therapies. Sodium acetate anhydrous is used as an electrolyte replenisher in isosmotic solution for parenteral replacement of acute losses of extracellular fluid without disturbing normal electrolyte balance.
|Molar mass||82.034 g·mol−1|
|Appearance||White deliquescent powder|
|Odor||Vinegar (acetic acid) odor when heated to decomposition|
|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)
|Solubility||soluble in alcohol, hydrazine, SO2|
Sodium Acetate is chemically designated CH3COONa, a hygroscopic powder very soluble in water. Sodium acetate could be used as additives in food, industry, concrete manufacture, heating pads, and in buffer solutions. Medically, sodium acetate is an important component as an electrolyte replenisher when given intravenously. It is mainly indicated to correct sodium levels in hyponatremic patients. It can be used also in metabolic acidosis and for urine alkalinization.
Sodium acetate is used as the carbon source for culturing bacteria. Sodium acetate is also useful for increasing yields of DNA isolation by ethanol precipitation.
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 the 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. Sodium acetate (anhydrous) is widely used as a shelf-life extending agent, pH control agent It is safe to eat at low concentrations.
A solution of sodium acetate (a basic salt of acetic acid) 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 melt at 136.4 °F/58 °C (to 137.12 °F/58.4 °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.