Potassium acetate

Potassium acetate
Identifiers
CAS number 127-08-2 Y
ChEMBL CHEMBL1201058 N
ATC code B05XA17
Properties
Molecular formula CH3CO2K
Molar mass 98.15 g/mol
Appearance White deliquescent crystalline powder
Density 1.57 g/cm3
Melting point

292 °C, 565 K, 558 °F

Solubility in water 253 g/100 mL (20 °C)
492 g/100 mL (62 °C)
Solubility soluble in methanol, ethanol, liquid ammonia
insoluble in ether, acetone
Acidity (pKa) 4.76
Hazards
EU classification not listed
NFPA 704
1
1
1
 N (verify) (what is: Y/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Potassium acetate (CH3CO2K) is the potassium salt of acetic acid.

Preparation

It can be prepared by reacting a potassium-containing base such as potassium hydroxide or potassium carbonate with acetic acid:

2 CH3COOH + K2CO3 → 2 CH3CO2K + CO2 + H2O

This sort of reaction is known as an acid-base neutralization reaction. Potassium acetate is the salt that forms along with water as acetic acid and potassium hydroxide are neutralized together.

Conditions/substances to avoid are: moisture, heat, flames, ignition sources, and strong oxidizing agents.

Applications

Potassium acetate can be used as a deicer instead of chloride salts such as calcium chloride or magnesium chloride. It offers the advantage of being less aggressive on soils and much less corrosive, and for this reason is preferred for airport runways. It is, however, more expensive. Potassium acetate is also the extinguishing agent used in class K fire extinguishers because of its ability to cool and form a crust over burning oils.

In medicine, potassium acetate is used as part of replacement protocols in the treatment of diabetic ketoacidosis because of its ability to break down into bicarbonate and help neutralize the acidotic state.

Potassium acetate is used as a food additive as a preservative and acidity regulator. In the European Union, it is labeled by the E number E261[1]; it is also approved for usage in the USA[2] and Australia and New Zealand.[3]

In molecular biology, potassium acetate is used to precipitate dodecyl sulfate (DS) and DS-bound proteins, allowing the removal of proteins from DNA. It is also used as a salt for the ethanol precipitation of DNA.

Potassium acetate is used in mixtures applied for tissue preservation, fixation, and mummification. Most museums today use the formaldehyde-based method recommended by Kaiserling in 1897 which contains potassium acetate.[4] For example, Lenin's mummy was soaked in a bath containing potassium acetate.[5]

Potassium acetate was originally used in the preparation of Cadet's fuming liquid, the first organometallic compound produced. It is used as diuretic and urinary alkaliser, and acts by changing the physical properties of the body fluids and by functioning as an alkali after absortion.

References