Ammonium thiocyanate

Ammonium thiocyanate

Identifiers
CAS Number	1762-95-4 N
3D model (Jmol)	Interactive image
ChEBI	CHEBI:30465 Y
ChemSpider	14901 N
ECHA InfoCard	100.015.614
PubChem	15666
RTECS number	XN6465000
InChI InChI=1S/CHNS.H3N/c2-1-3;/h3H;1H3 N Key: SOIFLUNRINLCBN-UHFFFAOYSA-N N InChI=1/CHNS.H3N/c2-1-3;/h3H;1H3 Key: SOIFLUNRINLCBN-UHFFFAOYAF
SMILES [S-]C#N.[NH4+]
Properties
Chemical formula	NH4SCN
Molar mass	76.122 g/mol
Appearance	Colorless hygroscopic crystalline solid
Density	1.305 g/cm3
Melting point	149.5 °C (301.1 °F; 422.6 K)
Boiling point	170 °C (338 °F; 443 K) (decomposes)
Solubility in water	128 g/100 mL (0 °C)
Solubility	soluble in liquid ammonia, alcohol, acetone
Magnetic susceptibility (χ)	-48.1·10−6 cm3/mol
Hazards
Safety data sheet	External MSDS
NFPA 704	1 2 1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Ammonium thiocyanate is an inorganic compound with the formula NH₄SCN. It is the salt of the ammonium cation and the thiocyanate anion.

Ammonium thiocyanate is used in the manufacture of herbicides, thiourea, and transparent artificial resins; in matches; as a stabilizing agent in photography; in various rustproofing compositions; as an adjuvant in textile dyeing and printing; as a tracer in oil fields; in the separation of hafnium from zirconium, and in titrimetric analyses.

Ammonium thiocyanate can also be used to determine the iron content in soft drinks by colorimetry.

Ammonium thiocyanate is made in the United States by the reaction of carbon disulfide with aqueous ammonia. Ammonium dithiocarbamate is formed as an intermediate in this reaction, which upon heating, decomposes to ammonium thiocyanate and hydrogen sulfide:

Ammonium thiocyanate is stable in air; however, upon heating it isomerizes to thiourea:

The equilibrium mixtures at 150 °C and 180 °C contain 30.3% and 25.3% (by weight) thiourea, respectively. When heated at 200 °C, the dry powder decomposes to ammonia, hydrogen sulfide, and carbon disulfide, leaving a residue of guanidinium thiocyanate.

NH₄SCN is weakly acidic; reacts with caustic soda or caustic potash to form sodium thiocyanate or potassium thiocyanate. It reacts with ferric salts to form a deep-red ferric thiocyanate complex: