Potassium thiocyanate

Last updated
Potassium thiocyanate
Potassium thiocyanate.png
Potassium-thiocyanate-xtal-3D-vdW-B.png
Crystals of Potassium Thiocyanate.jpg
Names
Other names
Potassium sulfocyanate
Potassium isothiocyanate (tautomeric form)
Potassium thiocyanide
Potassium rhodanide
Identifiers
3D model (JSmol)
3594799
ChEBI
ChemSpider
ECHA InfoCard 100.005.792 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 206-370-1
21362
PubChem CID
RTECS number
  • XL1925000
UNII
  • InChI=1S/CHNS.K/c2-1-3;/h3H;/q;+1/p-1 Yes check.svgY
    Key: ZNNZYHKDIALBAK-UHFFFAOYSA-M Yes check.svgY
  • InChI=1/CHNS.K/c2-1-3;/h3H;/q;+1/p-1
    Key: ZNNZYHKDIALBAK-REWHXWOFAT
  • C(#N)[S-].[K+]
Properties
KSCN
Molar mass 97.181 g mol−1
AppearanceColorless deliquescent crystals
Odor Odorless
Density 1.886 g/cm3
Melting point 173.2 °C (343.8 °F; 446.3 K)
Boiling point 500 °C (932 °F; 773 K) (decomposes)
177 g/100 mL (0 °C)
217 g/100 mL (20 °C)
Solubility acetone: 21.0 g/100 mL
ethanol: soluble
48.0·10−6 cm3/mol
Hazards
GHS labelling:
GHS-pictogram-acid.svg GHS-pictogram-exclam.svg
Warning
H302, H312, H318, H319, H332, H412
P261, P264, P270, P271, P273, P280, P301+P312, P302+P352, P304+P312, P304+P340, P305+P351+P338, P310, P312, P322, P330, P337+P313, P363, P501
NFPA 704 (fire diamond)
NFPA 704.svgHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
2
0
0
Lethal dose or concentration (LD, LC):
854 mg/kg (oral, rat) [1]
Safety data sheet (SDS) ICSC 1088
Related compounds
Other anions
Potassium cyanate
Potassium cyanide
Other cations
Sodium thiocyanate
Ammonium thiocyanate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Potassium thiocyanate is the chemical compound with the molecular formula KSCN. It is an important salt of the thiocyanate anion, one of the pseudohalides. The compound has a low melting point relative to most other inorganic salts.

Contents

Uses

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. [2]

KSCN converts ethylene carbonate to ethylene sulfide. [3] For this purpose, the KSCN is first melted under vacuum to remove water. In a related reaction, KSCN converts cyclohexene oxide to the corresponding episulfide and KOCN. [4]

KSCN is also the starting product for the synthesis of carbonyl sulfide.

Special effects

Dilute aqueous KSCN is occasionally used for moderately realistic blood effects in film and theatre. It can be painted onto a surface or kept as a colorless solution. When in contact with ferric chloride 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. 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.[ citation needed ]

Laboratory

The reaction with Fe Fe3+ mentioned above is used as a test for Fe3+ in the laboratory.

Law enforcement

Approximate cocaine purity can be determined using 1 mL 2% cupric sulphate pentahydrate in dilute HCl, 1 mL 2% potassium thiocyanate and 2 mL of chloroform. The shade of brown shown by the chloroform is proportional to the cocaine content. This test is not cross sensitive to heroin, methamphetamine, benzocaine, procaine and a number of other drugs but other chemicals could cause false positives. [5]

Related Research Articles

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<span class="mw-page-title-main">Potassium permanganate</span> Chemical compound

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4
, an intensely pink to purple solution.

<i>N</i>-Methylethanolamine Chemical compound

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Classical qualitative inorganic analysis is a method of analytical chemistry which seeks to find the elemental composition of inorganic compounds. It is mainly focused on detecting ions in an aqueous solution, therefore materials in other forms may need to be brought to this state before using standard methods. The solution is then treated with various reagents to test for reactions characteristic of certain ions, which may cause color change, precipitation and other visible changes.

<span class="mw-page-title-main">Oxalyl chloride</span> Chemical compound

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Potassium cyanate is an inorganic compound with the formula KOCN. It is a colourless solid. It is used to prepare many other compounds including useful herbicide. Worldwide production of the potassium and sodium salts was 20,000 tons in 2006.

<span class="mw-page-title-main">Episulfide</span> Organic compounds with a saturated carbon-carbon-sulfur ring

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 thiiranes, olefin sulfides, thioalkylene oxides, and thiacyclopropanes. Episulfides are less common and generally less stable than epoxides. The most common derivative is ethylene sulfide.

<span class="mw-page-title-main">Mercury(II) thiocyanate</span> Chemical compound

Mercury(II) thiocyanate (Hg(SCN)2) is an inorganic chemical compound, the coordination complex of Hg2+ and the thiocyanate anion. It is a white powder. It will produce a large, winding "snake" when ignited, an effect known as the Pharaoh's serpent.

<span class="mw-page-title-main">Sodium thiocyanate</span> Chemical compound

Sodium thiocyanate (sometimes called sodium sulphocyanide) is the chemical compound with the formula NaSCN. This colorless deliquescent salt is one of the main sources of the thiocyanate anion. As such, it is used as a precursor for the synthesis of pharmaceuticals and other specialty chemicals. Thiocyanate salts are typically prepared by the reaction of cyanide with elemental sulfur:

<span class="mw-page-title-main">Iodobenzene</span> Chemical compound

Iodobenzene is an aryl iodide and the simplest of the iodobenzenes, consisting of a benzene ring substituted with one iodine atom. Its chemical formula is C6H5I. It is useful as a synthetic intermediate in organic chemistry. It is a volatile colorless liquid, although aged samples appear yellowish.

<span class="mw-page-title-main">Thiirane</span> Chemical compound

Thiirane, more commonly known as ethylene sulfide, is the cyclic chemical compound with the formula C2H4S. It is the smallest sulfur-containing heterocycle and the simplest episulfide. Like many organosulfur compounds, this species has a highly unpleasant odour. Thiirane is also used to describe any derivative of the parent ethylene sulfide.

<span class="mw-page-title-main">Thioureas</span> Organosulfur compounds with an >NC(=S)N< structure

In organic chemistry, thioureas are members of a family of organosulfur compounds with the formula S=C(NR2)2 and structure R2N−C(=S)−NR2. The parent member of this class of compounds is thiourea. Substituted thioureas are found in several commercial chemicals.

<span class="mw-page-title-main">Thiocyanogen</span> Chemical compound

Thiocyanogen, (SCN)2, is a pseudohalogen derived from the pseudohalide thiocyanate, [SCN]. This hexatomic compound exhibits C2 point group symmetry and has the connectivity NCS-SCN. The oxidation ability is greater than bromine. It reacts with water:

<span class="mw-page-title-main">Cobalt(II) thiocyanate</span> Chemical compound

Cobalt(II) thiocyanate is an inorganic compound with the formula Co(SCN)2. The anhydrous compound is a coordination polymer with a layered structure. The trihydrate, Co(SCN)2(H2O)3, is a isothiocyanate complex used in the cobalt thiocyanate test (or Scott test) for detecting cocaine. The test has been responsible for widespread false positives and false convictions.

<span class="mw-page-title-main">Ammonium thiocyanate</span> Chemical compound

Ammonium thiocyanate is an inorganic compound with the formula [NH4]+[SCN]. It is an ammonium salt of thiocyanic acid. It consists of ammonium cations [NH4]+ and thiocyanate anions [SCN].

<span class="mw-page-title-main">Cyclopropylacetylene</span> Chemical compound

Cyclopropylacetylene is an hydrocarbon with the chemical formula C
5
H
6
. Under normal conditions, the substance is a colorless liquid. Cyclopropylacetylene is a precursor pharmaceuticals and other organic compounds.

References

  1. "Potassium thiocyanate [NF]". chem.sis.nlm.nih.gov. Archived from the original on 20 April 2018. Retrieved 19 April 2018.
  2. Smith, P. A. S.; Kan, R. O. (1973). "2a-Thiohomophthalimide". Organic Syntheses .; Collective Volume, vol. 5, p. 1051
  3. Searles, S.; Lutz, E. F.; Hays, H. R.; Mortensen, H. E. (1973). "Ethylenesulfide". Organic Syntheses .; Collective Volume, vol. 5, p. 562
  4. van Tamelen, E. E. (1963). "Cyclohexenesulfide". Organic Syntheses .; Collective Volume, vol. 4, p. 232
  5. Travnikoff B (1 April 1983). "Semiquantitative screening test for cocaine". Analytical Chemistry. 55 (4): 795–796. doi:10.1021/ac00255a048. ISSN   0003-2700.