Potassium thiocyanate, KSCN,also known as potassium sulfocyanate and potassium rhodanide, is a colorless deliquescent crystalline solid that melts at 173°C (343 OF) and decomposes at 500°C(932 OF). Soluble in water and alcohol,it has no odor and a saline taste.Potassium thiocyanate is used in printing and dyeing textiles, freezing mixtures, manufacturing chemicals, photography and medicine.
It is colorless monoclinic crystal. It is soluble in water, and it can cool because of the absorption of heat. It is also soluble in alcohol and acetone.
The above information is edited by the chemicalbook of Wang Xiaodong.
It can be used in electroplating industry for stripping agent, it can also be used refrigerant. It can also be used in the dye industry, photographic industry, pesticides and steel analysis.
manufacture of artificial mustard oil; printing and dyeing textiles; in photography as intensifier; in analytical chemistry. The sodium salt now is replacing it for most of these uses.
Analysis of siliver ion; indirect determination of chloride, bromide, and iodide.
Reference quality standards
Solubility in water (g / 100ml)
The grams which dissolved in per 100 ml of water at different temperatures (℃) :
177g/0 ℃; 198g/10 ℃; 224g/20 ℃; 255g/30 ℃; 289g/40 ℃
372g/60 ℃; 492g/80 ℃; 571g/90 ℃; 675g/100 ℃
Potassium thiocyanate, molecular formula is KSCN, it is also known as KSCN, English is Potassium Thiocyanate, it is colorless monoclinic crystal. The relative density is 1.886. Melting point is about 172.3 ℃. It is soluble in water and it can cool because of the absorption of heat, it is also soluble in alcohol (ethanol) and acetone. Crystalline hemihydrate (KSCN.0.5H2O) can be obtained at low temperature, it is steady at-29-6.8℃, and it can turn blue when be broiled at about 430℃, but it then re-becomes colorless when be colded. When be heated to 500℃, it can decompose. The blood red ferric thiocyanate complex ion FeSCN2 + (iron thiocyanate) can generate in case of Fe3 + (ferric), which is the sensitive method to test the Fe3 + ion, the method can eliminate the influence of all other known metal ions. And it can not react with ferrous salts. It is hygroscopic, and it should be sealed. It has low toxicity. But potassium cyanate is highly toxic substances, the country has limited its production.
The mothod of ammonium thiocyanate transformation which is the pressurized synthesis reaction of carbon disulfide and ammonia can generate ammonium thiocyanate and the by-product is ammonium hydrosulfide, and then by desulfurization, ammonium hydrosulfide can evaporate and remove which is decomposed into hydrogen sulfide, when potassium carbonate solution is added into the temperature of 105℃ liquid, it can generates potassium thiocyanate. The reaction process will produce large amount of carbon dioxide and ammonia. Ammonia is recyclable, the reaction solution is filtered to remove insoluble material, and then reduction vaporization is proceeded, and then cooling and crystallization, centrifugal separation is proceeded to obtain industrial potassium thiocyanate.
CS2 + 3NH3 → NH4SCN + NH4HS
NH4HS → NH3 ↑ + H2S ↑
2NH4SCN + K2CO3 → 2KSCN + (NH4) 2CO3
(NH4) 2CO3 → 2NH3 ↑ + CO2 ↑ + H2O
Crystallise it from H2O if much chloride ion is present in the salt, otherwise from EtOH or MeOH (optionally by addition of Et2O). Filter off on a Büchner funnel without paper, and dry it in a desiccator at room temperature before heating for 1hour at 150o, with a final 10-20minutes at 200o to remove the last traces of solvent [Kolthoff & Lingane J Am Chem Soc 57 126 1935]. Store it in the dark.
ChEBI: A potassium salt which is the monopotassium salt of thiocyanic acid.