Potassium thiocyanate is the

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

with the molecular formula KSCN. It is an important salt of the

thiocyanate Thiocyanate (also known as rhodanide) is the anion . It is the conjugate base of thiocyanic acid. Common derivatives include the colourless salts potassium thiocyanate and sodium thiocyanate. Mercury(II) thiocyanate was formerly used in pyr ...

anion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...

, one of the

pseudohalide Pseudohalogens are polyatomic analogues of halogens, whose chemistry, resembling that of the true halogens, allows them to substitute for halogens in several classes of chemical compounds. Pseudohalogens occur in pseudohalogen molecules, inorganic ...

s. The compound has a low melting point relative to most other inorganic salts.

Use in chemical synthesis

Aqueous KSCN reacts almost quantitatively with Pb(NO₃)₂ to give Pb(SCN)₂, which has been used to convert acyl chlorides to isothiocyanates. KSCN converts

ethylene carbonate Ethylene carbonate (sometimes abbreviated EC) is the organic compound with the formula (CH2O)2CO. It is classified as the cyclic carbonate ester of ethylene glycol and carbonic acid. At room temperature (25 °C) ethylene carbonate is a tran ...

to ethylenesulfide. For this purpose, the KSCN is first melted under vacuum to remove water. In a related reaction, KSCN converts

cyclohexene oxide Cyclohexene oxide is a Epoxy#Aliphatic, cycloaliphatic epoxide. It can react in cationic polymerization to poly(cyclohexene oxide). As cyclohexene is monovalent ion, monovalent, poly(cyclohexene oxide) is a thermoplastic. Production Cyclohexene ...

to the corresponding

episulfide In organic chemistry, episulfides are a class of organic compounds that contain a saturated, heterocyclic ring consisting of two carbon atoms and one sulfur atom. It is the sulfur analogue of an epoxide or aziridine. They are also known as thiir ...

. :C₆H₁₀O + KSCN → C₆H₁₀S + KOCN KSCN is also the starting product for the synthesis of

carbonyl sulfide Carbonyl sulfide is the chemical compound with the linear formula OCS. It is a colorless flammable gas with an unpleasant odor. It is a linear molecule consisting of a carbonyl group double bonded to a sulfur atom. Carbonyl sulfide can be consi ...

Other uses

Dilute aqueous KSCN is occasionally used for moderately realistic blood effects in film and theater. It can be painted onto a surface or kept as a colorless solution. When in contact with

ferric chloride Iron(III) chloride is the inorganic compound with the formula . Also called ferric chloride, it is a common compound of iron in the +3 oxidation state. The anhydrous compound is a crystalline solid with a melting point of 307.6 °C. The col ...

solution (or other solutions containing Fe³⁺), the product of the reaction is a solution with a blood red colour, due to the formation of the thiocyanatoiron

complex ion A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Many ...

. Thus this chemical is often used to create the effect of 'stigmata'. Because both solutions are colorless, they can be placed separately on each hand. When the hands are brought into contact, the solutions react and the effect looks remarkably like

stigmata Stigmata ( grc, στίγματα, plural of , 'mark, spot, brand'), in Roman Catholicism, are bodily wounds, scars and pain which appear in locations corresponding to the crucifixion wounds of Jesus Christ: the hands, wrists, and feet. Sti ...

. Similarly, this reaction is used as a

test Test(s), testing, or TEST may refer to: * Test (assessment), an educational assessment intended to measure the respondents' knowledge or other abilities Arts and entertainment * ''Test'' (2013 film), an American film * ''Test'' (2014 film), ...

for Fe³⁺ in the

laboratory A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratory services are provided in a variety of settings: physic ...

References

{{DEFAULTSORT:Potassium Thiocyanate Thiocyanates Potassium compounds Photographic chemicals