Potassium thiocyanide Potassium rhodanide
3D model (JSmol)
|Molar mass||97.181 g mol−1|
|Appearance||Colorless deliquescent crystals|
|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 in acetone||21.0 g/100 mL|
|Safety data sheet||ICSC 1088|
|R-phrases (outdated)||R20/21/22 R32 R52/53|
|S-phrases (outdated)||(S2) S13 S61|
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|854 mg/kg (oral, rat)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
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.
Use in chemical synthesis
KSCN converts ethylene carbonate to ethylenesulfide. 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.
- C6H10O + KSCN → C6H10S + KOCN
KSCN is also the starting product for the synthesis of carbonyl sulfide.
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 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.
- Smith, P. A. S.; Kan, R. O. (1973). "2a-Thiohomophthalimide". Org. Synth.; Coll. Vol., 5, p. 1051
- Searles, S.; Lutz, E. F.; Hays, H. R.; Mortensen, H. E. (1973). "Ethylenesulfide". Org. Synth.; Coll. Vol., 5, p. 562
- van Tamelen, E. E. (1963). "Cyclohexenesulfide". Org. Synth.; Coll. Vol., 4, p. 232