Name | Ammonium thiocyanate |
Synonyms | Ammoniumrhodantate Ammonium thiocyanate AMMoniuM thiocyanate powder Thiocyanic acid ammonium salt THIOCYANIC ACID AMMONIUM SALT thiocyanic acid, ammonium salt Ammonium thiocyanate concentrate |
CAS | 1762-95-4 |
EINECS | 217-175-6 |
InChI | InChI=1/CHNO3S.H3N/c2-1-6(3,4)5;/h(H,3,4,5);1H3/p+1 |
Molecular Formula | CH4N2S |
Molar Mass | 76.12 |
Density | 1.3 |
Melting Point | 152-154 °C (lit.) |
Boling Point | 262.85°C |
Flash Point | 190 °C |
Water Solubility | 163 g/100 mL (20 ºC) |
Solubility | H2O: 1M at20°C, clear, colorless |
Vapor Presure | <1 hPa (20 °C) |
Appearance | Colorless crystal |
Specific Gravity | 1.305 |
Color | clear colorless or white |
Odor | Odorless |
Exposure Limit | NIOSH: IDLH 25 mg/m3 |
Merck | 14,561 |
BRN | 3595135 |
PH | 4.8-5.8 (50g/l, H2O, 20℃) |
Storage Condition | Store at +5°C to +30°C. |
Stability | Stable. Incompatible with strong acids, strong oxidizing agents. Forms explosive mixtures with lead nitrate. |
Sensitive | Light Sensitive & Hygroscopic |
Refractive Index | 1.5300 (estimate) |
MDL | MFCD00011428 |
Physical and Chemical Properties | Characteristics of colorless monoclinic plate-like or columnar crystals, glossy. melting point 149.6 ℃ relative density 1.306 solubility: soluble in water, ethanol, liquid ammonia, acetone, pyridine and liquid sulfur dioxide. |
Use | Used as auxiliary raw materials for hydrogen peroxide, also used in dyes, organic synthesis, pesticides, pharmaceuticals, etc |
Risk Codes | R20/21/22 - Harmful by inhalation, in contact with skin and if swallowed. R32 - Contact with acids liberates very toxic gas R52/53 - Harmful to aquatic organisms, may cause long-term adverse effects in the aquatic environment. R36/37/38 - Irritating to eyes, respiratory system and skin. |
Safety Description | S13 - Keep away from food, drink and animal foodstuffs. S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. S36/37 - Wear suitable protective clothing and gloves. S36 - Wear suitable protective clothing. S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S46 - If swallowed, seek medical advice immediately and show this container or label. |
UN IDs | 9092 |
WGK Germany | 1 |
RTECS | XK7875000 |
FLUKA BRAND F CODES | 3 |
TSCA | Yes |
HS Code | 28380000 |
Toxicity | LD50 orally in Rabbit: 500 mg/kg |
colorless leaf-like or columnar crystals. mp: about 149 °c; dl. 305. Easy deliquescence, soluble in water, the water solution of iron salt solution showed blood red, ferrous salt is no reaction. Soluble in ethanol, soluble in methanol, acetone, insoluble in chloroform, ethyl acetate. Heat to 200~300 deg C, the decomposition of ammonia, carbon disulfide, hydrogen sulfide. With lead nitrate, chloride, nitric acid and other intense reaction. Flammable, but not easy to ignite. Fire can produce toxic gases.
The carbon disulfide and ammonia water are subjected to pressurized synthesis reaction to generate ammonium thiocyanate and by-product ammonium hydrosulfide, and then the ammonium hydrosulfide is decomposed to generate hydrogen sulfide by desulfurization and evaporation, after removal of impurities and separation of the resulting solution, the product was obtained. Alternatively, sodium thiocyanate is formed by the reaction of sulfur with sodium cyanide, and then metathesis with ammonium chloride to form ammonium sulfate.
assay and determination of trace iron, silver and Mercury. For the separation of antibiotics, analysis of pesticide content, water analysis, preparation of thiocyanate and standard solution. It is also used in the synthesis of thiocyanate, thiocyanate and as a polymerization catalyst.
has a irritating effect on the eyes and skin. Rinse with plenty of water to avoid exposure to potassium chloride and lead nitrate. Store in a cool, ventilated warehouse to prevent direct sunlight. Keep away from fire and heat source. Keep the container sealed. Should be stored separately from oxidants and acids.
pH indicator color change ph range | 4.5 - 6.0 |
LogP | 0.58 |
EPA chemical information | Information provided by: ofmpub.epa.gov (external link) |
Overview | Ammonium thiocyanate, also known as ammonium thiocyanate, ammonium thiocyanate, colorless and glossy monoclinic system flake or columnar crystal, chemical formula NH4SCN, molecular weight 76.12, rhombus crystal at 92 ℃. Melting point 147 ℃ (decomposition at 170 ℃), relative density 1.3057, refractive index 1.685. Easily soluble in water, it is an endothermic reaction when dissolved in water, soluble in ethanol, alkali metal hydroxide, acetone, pyridine and liquid sulfur dioxide, and hardly soluble in chloroform (chloroform). The solution is red under sunlight. In case of iron salt, blood red iron thiocyanide is generated, which can be compared with the color of the standard solution for colorimetric quantitative determination. Thiourea is formed when heated to about 140 ℃. Decompose into ammonia, carbon disulfide and hydrogen sulfide at 176 ℃. Easy to deliquesce in the air, should be sealed storage, isolated from acids. preparation method: carbon disulfide and liquid ammonia are reacted in a pressurized reactor at a temperature of 30 ℃ for 20 hours, or sulfur powder, sodium cyanide and ammonium chloride are reacted with water at a temperature of about 110 ℃. Main Uses: Used as polymerization catalyst for organic synthesis, printing and dyeing diffusion agent, pesticide herbicide, analytical reagent, such as determination of silver mercury and trace iron, and can also make thiocyanate and thiocyanate complex salt. It has certain dissolving ability to silver halide, and its concentrated solution also has the ability to dissolve gelatin. Used for photographic liquid medicine, gold color mixing of printing paper, printing of cotton fabrics, acid soaking of steel, etc. |
industrial ammonium thiocyanate | industrial ammonium thiocyanate is one of the coke oven gas purification products. the pure product is colorless and shiny monoclinic crystal with molecular formula NH4SCN and density of 1.305g/cm3. it is easy to deliquesce in air, soluble in water (a large amount of heat absorption when dissolving industrial ammonium thiocyanate production system), melting point is 149.6 ℃, and decomposes at 170 ℃. Ammonium thiocyanate is mainly used in the dyeing industry, and is also used as a chemical reagent and a herbicidal agent. In the process of coke oven gas purification, when hydrogen cyanide is directly removed from the gas by ammonium polysulfide solution, industrial ammonium thiocyanate products with a content of more than 92% are obtained. the absorption reaction formula for decyanation of coke oven gas is: HCN + (NH4) 2Sn → HSCN + (NH4) 2Sn-1 NH3 + HSCN → NH4SCN NH3 + HCN → NH4CN NH4CN + (NH4) 2Sn → NH4SCN + (NH4) 2Sn-1 the ammonia participating in the absorption reaction comes from coke oven gas itself, therefore, the decyanation device must be located before the coke oven gas recovery ammonia process. After the coke oven gas is removed by the electric tar trap, the tar mist and naphthalene are removed, and then the hydrogen cyanide in the gas is removed by the ammonium polysulfide solution to generate ammonium thiocyanate. The absorption liquid continuously circulates the washing gas to increase the concentration of ammonium thiocyanate in the absorption liquid, and at the same time continuously takes out a part of the absorption liquid and regenerates with sulfur. The regeneration reaction formula is (NH4)2Sn-1 S →(NH4)2Sn. When the content of ammonium thiocyanate in the absorption solution reaches 250g/L, it can be taken out and sent for processing. After evaporation and crystallization, industrial ammonium thiocyanate products are produced. |
thiocyanate | thiocyanate has two isomers, one is thiocyanate H-S-C ≡ N, the other is isothiocyanate H-N-C = S. Free acid has not been isolated. Most thiocyanates are soluble in water. SCN-ion is a good ligand. A particularly sensitive reaction of SCN-ion is to form a variety of red complexes with Fe3. Therefore, potassium thiocyanate or ammonium thiocyanate is often used as a reagent for testing Fe3. Colorless volatile liquid, slightly toxic. Melting point -110 ℃, stable at 0 ℃, rapid decomposition at room temperature. Easily soluble in water, the aqueous solution is strongly acidic. Its hot solution or concentrated solution is easy to decompose and easy to polymerize. Polymerized into white crystals at -90 ~-85 ℃. It is heated in a vacuum to form a light yellow thiocyanuric acid dissolved in ether, which is easily decomposed into thiocyanic acid. It is prepared by the interaction of potassium thiocyanate with potassium bisulfate or by passing an aqueous solution of ammonium thiocyanate through an H-type cation exchange resin. Reagents for testing iron and quantitative determination of silver in the laboratory. |
Potassium thiocyanate | Potassium thiocyanate is also called "potassium thiocyanate". Chemical formula KSCN. Molecular weight 97.18. Colorless orthorhombic crystal. There is deliquescence. Poisonous! irritating the skin. Melting point 173.2 ℃, relative density 1.88614. When the melt cools, it turns into brown, green, blue and white. Easily soluble in water, neutral in aqueous solution, soluble in acetone, ethanol and liquid ammonia. Decomposition at 500 ℃. Preparation method: Potassium cyanide and sulfur powder are heated together, or ammonium thiocyanate and potassium hydroxide are combined. Uses: used in the preparation of mustard oil, thiourea, drugs, used in printing and dyeing industry, photography, used as a refrigerant, analytical reagents. |
solubility in water (g/100ml) | dissolution grams per 100ml of water at different temperatures (℃): 120g/0 ℃;144g/10 ℃;170g/20 ℃;208g/30 ℃;234g/40 ℃ 346g/60 ℃ |
toxicity | see sodium thiocyanate. |
Use | Used as a polymerization catalyst for dyes and organic synthesis, used for pesticide weeding and the separation of defoliants and antibiotics, and is also a raw material for the production of cyanide and thiourea Used as an auxiliary raw material for the production of hydrogen peroxide, and also used in dyes, organic synthesis, pesticides, medicine, etc. is an auxiliary raw material for the production of hydrogen peroxide. Used as a polymerization catalyst for dyes and organic synthesis. Used for the separation of pesticides and antibiotics, analytical reagents, etc. It is also a raw material for the manufacture of cyanide, ferrocyanide and thiourea. It is also used for zinc coating, printing and dyeing diffuser, electroplating additive. as an analytical reagent, also used for the separation of antibiotics verification and determination of trace iron, determination of silver and mercury, polymerization catalyst, separation of antibiotics, analysis of pesticide content, water quality analysis, preparation of thiocyanate and standard solution. |
production method | carbon disulfide method mixes carbon disulfide and slightly excess liquid ammonia with water, and reacts at a pressure of 5.88 × 105Pa and a temperature of 100 ℃ for about 20h to generate ammonium thiocyanate. The reaction solution is evaporated under reduced pressure to remove hydrogen sulfide. When the liquid temperature is 105 ℃, ammonium sulfide is used to remove iron and heavy metals, filter, concentrate the filtrate under reduced pressure, cool and crystallize in the crystallizer, and then centrifuge and dry to obtain Ammonium thiocyanate. Its CS2 3NH3 → NH4SCN NH4HSNH4HS → NH3 ↑ H2S ↑ sulfur method stirs a proper amount of water and sulfur powder in the reactor into a slurry, solid sodium cyanide is slowly added in stages, and the reaction is carried out at a temperature of about 110 ℃ to generate sodium thiocyanide, and then solid ammonium chloride is added to the reaction to generate ammonium thiocyanate, barium thiocyanate is added to the reaction solution, impurity removal and clarification, and the supernatant is evaporated under reduced pressure and concentrated to precipitate sodium chloride, after filtration, cooling crystallization, separation and drying, ammonium thiocyanate is prepared. Its NaCN S → NaSCNNaSCN NH4Cl → NaCl NH4SCN |
category | toxic substances |
toxicity classification | highly toxic |
acute toxicity | oral-rat LD50: 750 mg/kg; Oral-mouse LD50: 500 mg/kg |
flammability hazard characteristics | Toxic nitrogen oxides, sulfur oxides, cyanide and ammonia smoke are produced when heated |
storage and transportation characteristics | warehouse ventilation and low temperature drying; Store separately from potassium perchlorate |
fire extinguishing agent | dry powder, foam, sand, carbon dioxide, mist water |
occupational standard | STEL 5 mg/m3 |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |