Potassium nitrite

Potassium nitrite, E249

Colorless to yellowish, slightly deliquescent, hygroscopic, prismatic crystals

Fixed

1.92 g · cm -3

441 ° C

Decomposition

Very well in water ( 2810 g · l-1 at 20 ° C)

Risk

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Potassium nitrite, KNO2 (also: potassium nitrite, English: potassium nitrite ), is the potassium salt of nitrous acid HNO2.

Properties

Potassium nitrite forms colorless to slightly yellowish, strongly hygroscopic crystals which dissolve readily in water under cooling, the solution is alkaline. The crystals decompose above 360 ° C. Otherwise, it behaves similarly to sodium nitrite, which means it is oxidizing (especially at higher temperatures) and reacts violently with metals such as aluminum (especially in powder form! ), Dry ammonium compounds ( such as ammonium sulfate), cyanides and many organic compounds. It is a reducing agent and is oxidized in the air slowly potassium nitrate KNO3.

Potassium nitrite is toxic; generally nitrites can react with certain amines under suitable conditions to carcinogenic nitrosamines. Nitrite can be used with iron ( II) sulfate, and concentrated sulfuric acid demonstrated by brown coloring.

Occurrence and production

In nature, nitrites occur as intermediates in the nitrogen cycle - both in the nitrification ( nitrogen fixation ) and during denitrification ( nitrogen release ). Technically you win potassium nitrite by the action of nitric oxide on potassium carbonate solution.

Use

Potassium nitrite may 249 (preservative ) can be used under certain conditions in the nitrite (sodium chloride with potassium nitrite and sodium nitrite ) as a food additive under the E number. It gives the meat through the formation of nitrosomyoglobin a permanent red color. Meat and sausage products may contain a multiple of the drinking water limit of nitrite.