Chemistry:Potassium thiocyanate
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| Names | |
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| Other names
Potassium sulfocyanate
Potassium isothiocyanate (tautomeric form) Potassium thiocyanide Potassium rhodanide | |
| Identifiers | |
3D model (JSmol)
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| 3594799 | |
| ChEBI | |
| ChemSpider | |
| EC Number |
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| 21362 | |
PubChem CID
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| RTECS number |
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| UNII | |
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| Properties | |
| KSCN | |
| Molar mass | 97.181 g mol−1 |
| Appearance | Colorless 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) | |
| −48.0·10−6 cm3/mol | |
| Hazards | |
| Safety data sheet | ICSC 1088 |
| GHS pictograms |  
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| GHS Signal word | Warning |
| H302, H312, H318, H319, H332, H412 | |
| P261, P264, P270, P271, P273, P280, P301+312, P302+352, P304+312, P304+340, P305+351+338, P310, P312, P322, P330, P337+313, P363, P501 | |
| NFPA 704 (fire diamond) | |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose)
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854 mg/kg (oral, rat)[1] |
| Related compounds | |
Other anions
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Potassium cyanate Potassium cyanide |
Other cations
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Sodium thiocyanate Ammonium thiocyanate |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
 verify (what is   ?)
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| Infobox references | |
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.
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]
- C
6H
10O + KSCN → C
6H
10S + KOCN
KSCN is also the starting product for the synthesis of carbonyl sulfide.
Special effects
Laboratory
The reaction with Fe3+ mentioned above is used as a test for Fe3+ ions 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]
References
- ↑ "Potassium thiocyanate [NF"]. https://pubchem.ncbi.nlm.nih.gov/#tab/sidsrcname=ChemIDplus&query=333-20-0&input_type=text.
- ↑ Smith, P. A. S.; Kan, R. O. (1973). "2a-Thiohomophthalimide". Organic Syntheses. http://www.orgsyn.org/demo.aspx?prep=cv5p1051.; Collective Volume, 5, pp. 1051
- ↑ Searles, S.; Lutz, E. F.; Hays, H. R.; Mortensen, H. E. (1973). "Ethylenesulfide". Organic Syntheses. http://www.orgsyn.org/demo.aspx?prep=cv5p0562.; Collective Volume, 5, pp. 562
- ↑ van Tamelen, E. E. (1963). "Cyclohexenesulfide". Organic Syntheses. http://www.orgsyn.org/demo.aspx?prep=cv4p0232.; Collective Volume, 4, pp. 232
- ↑ "Semiquantitative screening test for cocaine". Analytical Chemistry 55 (4): 795–796. 1 April 1983. doi:10.1021/ac00255a048. ISSN 0003-2700.
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