Potassium thiocyanate

Potassium thiocyanate

Deliquescent, hygroscopic crystals

Fixed

1.89 g · cm -3

175 ° C.

Decomposition: 500 ° C

<1 hPa ( 20 ° C)

Readily soluble in water ( 208 g · l-1 at 20 ° C)

Attention

• 854 mg · kg -1 ( LD50, rat, oral)

-200.2 KJ / mol

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Potassium thiocyanate ( KSCN also: potassium thiocyanate ) is a salt of thiocyanic ( hydrogen thiocyanate acid).

Properties

Potassium thiocyanate at room temperature consists of crystals that dissolve slowly in the air. It dissolves very well in water, the solution cools rapidly. The melting temperature is about 175 ° C. The crystals are readily soluble in ethanol and acetone.

Production

Can be prepared by fusing together potassium potassium cyanide and potassium hydroxide solution and ammonium thiocyanate or sulfur. This in turn can be obtained from carbon disulphide and ammonia under pressure and at elevated temperature:

Use

Potassium thiocyanate is used as evidence for the present in aqueous solutions of Fe3 ions. The detection reaction based on the formation of Eisentrithiocyanat (Fe ( SCN ) 3), which is blood red in aqueous solution:

Potassium thiocyanate can be used as a detection reagent for copper ( II) ions. These are copper (II ) ions with sodium sulfite solution to copper ( I) ions is reduced, which together with thiocyanate a colorless precipitate:

Similarly, cobalt ( II) ions can be detected with potassium thiocyanate. This results in water red-violet cobalt ( II ) thiocyanate, which is blue on addition of alcohols or acetone.

Other applications include the production of freezing mixtures, pesticides, plastics, and metal pickling. It is also used in photography for tinting of images.