Posted in United States forum
Caluanie (Oxidative parterization thermostat, Heavy water)
"Caluanie"
muelear oxidize parteurize
Muelear Oxidize Parteurize Thermostat Harmfu Thermos
Manufacturer: USA.
Isocyanic acid General Chem. formulaRac. formula Physical properties Molar mass Density Thermal properties T. melt.T. kip Enthalpy of formation Specific heat of evaporation Vapor pressure Chemical properties pK a Structure Crystal structure Classification Reg. number CASPubChemReg. number EINECSSMILESInChI ChEBI ChemSpider Safety Toxicity
Isocyansäure.svg
HN=C=O
CHNO
43.03 g/mol
1.14 g/cm³
-86 °C [1]
23.5 °C
-153.3 kJ/mol
28.4 kJ/mol
36.13 kPa (273.16 K)
3.47 (in aqueous solutions)
crystals of the orthorhombic system (a = 1.082 nm, b = 0.523 nm, c = 0.357 nm, Z = 4, space group Pnma [2] )
75-13-8
6347
616-189-3
[show]
[show]
29202
6107
highly toxic
NFPA 704.svg341
Data given is based on standard conditions (25 °C, 100 kPa) unless otherwise stated.
Isocyanic acid, a colorless liquid with a pungent odor similar to acetic acid, is a stable tautomeric form of cyanic acid HOCN. Toxic. Salts of cyanic acid were first described by Wöhler in 1824; cyanic acid itself was obtained by Liebig and Wöhler in 1830. It is an isomer of fulmic (paracyanoic) acid (HC≡N→O). Forms salts - isocyanates.
Properties and reactivity
Isocyanic acid is a weak acid (K a = 3.47⋅10 −4 in aqueous solutions), stable in solutions in diethyl ether, benzene and toluene; in aqueous solutions it hydrolyzes to form carbon dioxide and ammonia, hydrolysis is accelerated in the presence of mineral acids:
{\mathsf {HNCO+H_{2}O\rightarrow NH_{3}+CO_{2}}}
The carbon atom of isocyanic acid is an electrophilic center: cyanic acid reacts with nucleophiles such as ammonia, amines and alcohols, forming the corresponding addition products.
When isocyanic acid reacts with alcohols, urethanes are formed:
{\mathsf {ROH+HNCO\rightarrow H_{2}N{\text{-}}COOR}}
which, with an excess of isocyanic acid, form allophane acid esters:
{\mathsf {HNCO+H_{2}N{\text{-}}CO{\text{-}}COOR\rightarrow H_{2}N{\text{-}}CO{\text{-}}NH {\text{-}}COOR}}
The interaction of isocyanic acid with ammonia leads to the formation of ammonium cyanate, which, when heated, isomerizes into urea; this reaction, discovered by Wöhler in 1828, became the first synthesis of an organic compound from inorganic substances [4] :
Urea Synthesis Woehler.png
Isocyanic acid reacts similarly with other nitrogenous nucleophiles: thus, amines add to it to form substituted ureas [5] , [6] :
{\mathsf {RNH_{2}+HNCO\rightarrow R{\text{-}}NH{\text{-}}CO{\text{-}}NH_{2}}}
and hydrazine, which reacts with isocyanic acid to form semicarbazide:
{\mathsf {H_{2}N{\text{-}}NH_{2}+HNCO\rightarrow H_{2}N{\text{-}}NH{\text{-}}CO{\text{- }}NH_{2}}}
Anhydrous isocyanic acid spontaneously polymerizes into a solid white mass consisting primarily of cyamelide, a linear polymer (-OC(=NH)-) n , and a trimer, cyanuric acid, which depolymerizes when heated to form the original acid.
Under the influence of triethylphosphine and tertiary amines, isocyanic acid trimerizes to form cyanuric acid (2,3,5-trihydroxy-sym-triazine).
Like mineral acids, isocyanic acid adds to alkenes to form alkyl isocyanates; alkenes with a terminal double bond and an electron-donating substituent at the double bond react most easily, for example, vinyl ethers:
{\mathsf {RO{\text{-}}CH{\text{=}}CH_{2}+HNCO\rightarrow RO{\text{-}}CH(CH_{3}){\text{-}} N{\text{=}}C{\text{=}}O}}
Styrene and its homologues, isoprene and other alkenes react similarly with isocyanic acid; the reaction with non-activated electron-donor alkenes takes place under more stringent conditions and under the influence of catalysts (boron trifluoride ether, p-toluenesulfonic acid) [7] .
Synthesis
A laboratory method for the synthesis of isocyanic acid is the thermal decomposition of cyanuric acid. The reaction is carried out at ~400 °C using purified cyanuric acid (impurities can lead to explosive decomposition); in industry, isocyanic acid is obtained by the catalytic oxidation of hydrocyanic acid at 630-650 °C on a gold contact grid.
Cyanates can be obtained by oxidation of alkali metal cyanides: for example, when potassium cyanide is melted in air, it becomes contaminated with potassium cyanate formed as a result of oxidation; the oxidation of sodium and potassium cyanides with air or oxygen in the presence of nickel is an industrial method for the synthesis of cyanates. Sodium and potassium cyanates are also synthesized by fusing the corresponding cyanides with lead oxide or lead lead Pb 3 O 4 . Hydrogen peroxide also oxidizes cyanides to cyanates.
Toxicity
Isocyanic acid is poisonous, like all cyanic acids.
Isocyanic acid, a colorless liquid with a pungent odor similar to acetic acid, is a stable tautomeric form of cyanic acid HOCN. Toxic. Salts of cyanic acid were first described by Wöhler in 1824; cyanic acid itself was obtained by Liebig and Wöhler in 1830. It is an isomer of fulmic (paracyanoic) acid (HC≡N→O). Forms salts - isocyanates.
Isocyanic acid
Isocyansäure
General Chem. formulaRac. formula Physical properties Molar mass Density Thermal properties T. melt.T. kip Enthalpy of formation Specific heat of evaporation Vapor pressure Chemical properties pK a Structure Crystal structure Classification Reg. number CASPubChemReg. number EINECSSMILESInChI ChEBI ChemSpider Safety Toxicity
HN=C=O
CHNO
43.03 g/mol
1.14 g/cm³
-86 °C [1]
23.5 °C
-153.3 kJ/mol
28.4 kJ/mol
36.13 kPa (273.16 K)
3.47 (in aqueous solutions)
crystals of the orthorhombic system (a = 1.082 nm, b = 0.523 nm, c = 0.357 nm, Z = 4, space group Pnma [2] )
75-13-8
6347
616-189-3
O=C=[N@H]
1S/CHNO/c2-1-3/h2H
OWIKHYCFFJSOEH-UHFFFAOYSA-N
29202
6107
highly toxic
NFPA 704
341
Data given is based on standard conditions (25 °C, 100 kPa) unless otherwise stated.
Properties and reactivity
Isocyanic acid is a weak acid (K a = 3.47⋅10 −4 in aqueous solutions), stable in solutions in diethyl ether, benzene and toluene; in aqueous solutions it hydrolyzes to form carbon dioxide and ammonia, hydrolysis is accelerated in the presence of mineral acids:
{\mathsf {HNCO+H_{2}O\rightarrow NH_{3}+CO_{2}}}
The carbon atom of isocyanic acid is an electrophilic center: cyanic acid reacts with nucleophiles such as ammonia, amines and alcohols, forming the corresponding addition products.
When isocyanic acid reacts with alcohols, urethanes are formed:
{\mathsf {ROH+HNCO\rightarrow H_{2}N{\text{-}}COOR}}
which, with an excess of isocyanic acid, form allophane acid esters:
{\mathsf {HNCO+H_{2}N{\text{-}}CO{\text{-}}COOR\rightarrow H_{2}N{\text{-}}CO{\text{-}}NH {\text{-}}COOR}}
The interaction of isocyanic acid with ammonia leads to the formation of ammonium cyanate, which, when heated, isomerizes into urea; this reaction, discovered by Wöhler in 1828, became the first synthesis of an organic compound from inorganic substances [4] :
Urea Synthesis Woehler
Urea Synthesis Woehler
Isocyanic acid reacts similarly with other nitrogenous nucleophiles: thus, amines add to it to form substituted ureas [5] , [6] :
{\mathsf {RNH_{2}+HNCO\rightarrow R{\text{-}}NH{\text{-}}CO{\text{-}}NH_{2}}}
and hydrazine, which reacts with isocyanic acid to form semicarbazide:
{\mathsf {H_{2}N{\text{-}}NH_{2}+HNCO\rightarrow H_{2}N{\text{-}}NH{\text{-}}CO{\text{- }}NH_{2}}}
Anhydrous isocyanic acid spontaneously polymerizes into a solid white mass consisting primarily of cyamelide, a linear polymer (-OC(=NH)-) n , and a trimer, cyanuric acid, which depolymerizes when heated to form the original acid.
Under the influence of triethylphosphine and tertiary amines, isocyanic acid trimerizes to form cyanuric acid (2,3,5-trihydroxy-sym-triazine).
Like mineral acids, isocyanic acid adds to alkenes to form alkyl isocyanates; alkenes with a terminal double bond and an electron-donating substituent at the double bond react most easily, for example, vinyl ethers:
{\mathsf {RO{\text{-}}CH{\text{=}}CH_{2}+HNCO\rightarrow RO{\text{-}}CH(CH_{3}){\text{-}} N{\text{=}}C{\text{=}}O}}
Styrene and its homologues, isoprene and other alkenes react similarly with isocyanic acid; the reaction with non-activated electron-donor alkenes takes place under more stringent conditions and under the influence of catalysts (boron trifluoride ether, p-toluenesulfonic acid) [7] .
Synthesis
A laboratory method for the synthesis of isocyanic acid is the thermal decomposition of cyanuric acid. The reaction is carried out at ~400 °C using purified cyanuric acid (impurities can lead to explosive decomposition); in industry, isocyanic acid is obtained by the catalytic oxidation of hydrocyanic acid at 630-650 °C on a gold contact grid.
Cyanates can be obtained by oxidation of alkali metal cyanides: for example, when potassium cyanide is melted in air, it becomes contaminated with potassium cyanate formed as a result of oxidation; the oxidation of sodium and potassium cyanides with air or oxygen in the presence of nickel is an industrial method for the synthesis of cyanates. Sodium and potassium cyanates are also synthesized by fusing the corresponding cyanides with lead oxide or lead lead Pb 3 O 4 . Hydrogen peroxide also oxidizes cyanides to cyanates.
Toxicity
Isocyanic acid is poisonous, like all cyanic acids.
AdBlue
AdBlue is a liquid reagent used to purify diesel engine exhaust gases using the selective catalytic reduction method. It is an aqueous solution consisting of 32.5% highly purified urea and 67.5% demineralized water. The AdBlue reagent allows you to reduce the content of nitrogen oxides (NOx) in the exhaust of diesel engines by 90%. The rights to the AdBlue trademark are owned by the Association of the German Automotive Industry (VDA). The requirements for the AdBlue reagent are determined by the international standard ISO 22241 or the German DIN 70070. In Russia, these standards correspond to GOST R ISO 22241.
In some countries this reagent is known as AUS 32 (Aqueous Urea Solution 32), and in North America as DEF (Diesel Exhaust Fluid).
The AdBlue reagent is injected into the exhaust pipe, as a result of a selective catalytic reaction, nitrogen oxides and ammonia are converted into harmless nitrogen and water vapor.
Price per canister (1 piece) - 5 l.
[...]
+15412493874
https://caluaniemuelearusa.com
