It can be prepared by reacting a potassium-containing base such as potassium hydroxide or potassium carbonate with acetic acid: 2CH3COOH + K2CO3 → 2CH3COOK + 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.
Potassium acetate is the extinguishing agent used in class K fire extinguishers because of its ability to cool and form a crust over the burning oils.
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.
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 as a food additive (preservative, acidity regulator) found on food labels in the European Union.
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 and containing potassium acetate. For example, Lenin's mummy was soaked in a bath containing potassium acetate.