Alkali hydrogen difluoride

Examples of toxic compounds, including some important intermediates and starting materials in the chemical industry, are shown in Figure 3.3. Many alkali fluorides, such as alkali hexafluorosilicate, alkali hydrogen difluoride, or alkali sulfuryl fluoride, are well known toxic substances. Sulfur dioxide and ammonia (ubiquitous gases) are toxic, as are chlorine, metallic mercury vapors, many organic phenol compounds, amino aromatic compounds such as aniline, and many substituted amino-benzene derivatives. Additionally, many diisocyanates are toxic, e.g., 2,4- and 2,6-toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), chloro-, bromo-, and iodoacetic acid, methyl bromide, tribromomethane (bromoform), carbon tetrachloride, and formaldehyde. Also, many natural compounds present in many plants have toxic properties, and a selection of these are listed in Table 3.4. 

AMMONIUM HYDROGEN DIFLUORIDE (1341-49-7) Reacts with water, forming a weak solution of hydrofluoric acid. Incompatible with alkalis, acids. Attacks glass, cement, and most metals in the presence of moisture. Flammable hydrogen gas may collect in enclosed spaces. 

Potentially explosive reaction with nitric acid + sulfuric acid, bromine trifluoride, nitrosyl chloride + platinum, nitrosyl perchlorate, chromyl chloride, thiotrithiazyl perchlorate, and (2,4,6-trichloro-l, 3,5-triazine + water). Reacts to form explosive peroxide products with 2-methyl-1,3-butadiene, hydrogen peroxide, and peroxomonosulfuric acid. Ignites on contact with activated carbon, chromium trioxide, dioxygen difluoride + carbon dioxide, and potassium-tert-butoxide. Reacts violendy with bromoform, chloroform + alkalies, bromine, and sulfur dichloride. 

Fluorine is the most electronegative of all the elements, so that the bonds it forms with most other elements have considerable ionic character. With the exception of the alkali halides most crystalline fluorides have structures different from those of the other halides of the same metal. A number of difluorides and dioxides have the same crystal structure, whereas the corresponding dichlorides, dibromides, and diiodides have in many cases structures similar to those of disulphides, diselenides, and ditellurides. The extreme electronegativity of fluorine enables it to form much stronger hydrogen bonds than any other element, resulting in the abnormal properties of HF as compared with the other acids HX, the much... 

CALCIUM DIFLUORIDE (7789-75-5) CaFj Noncombustible solid. Reacts with acids, liberating hydrogen fluoride fumes production of HF increases with teir erature. Incompatible with mineral acids alkalis, ammonia, aliphatic amines, alkanolamines, alkylene oxides, amides, epichlorohydrin, nitromethane, organic anhydrides, isocyanates, vinyl acetate. 

CAURZO (Spanish) (14808-60-7) Dust and powder react with powerful oxidizers (fluorine, chlorine trifluoride, manganese trioxide, oxygen difluoride, etc.) may cause fire and explosions. Attacked by hydrogen fluoride and alkali solutions. 

ESTANO (Spanish) (7440-31-5) Finely divided material is combustible and forms explosive mixture with air. Contact with moisture in air forms tin dioxide. Violent reaction with strong acids, strong oxidizers, ammonium perchlorate, ammonium nitrate, bis-o-azido benzoyl peroxide, bromates, bromine, bromine pentafluoride, bromine trifluoride, bromine azide, cadmium, carbon tetrachloride, chlorine, chlorine monofluoride, chlorine nitrate, chlorine pentafluoride, chlorites, copper(II) nitrate, fluorine, hydriodic acid, dimethylarsinic acid, ni-trosyl fluoride, oxygen difluoride, perchlorates, perchloroethylene, potassium dioxide, phosphorus pentoxide, sulfur, sulfur dichloride. Reacts with alkalis, forming flammable hydrogen gas. Incompatible with arsenic compounds, azochloramide, benzene diazonium-4-sulfonate, benzyl chloride, chloric acid, cobalt chloride, copper oxide, 3,3 -dichloro-4,4 -diamin-odiphenylmethane, hexafluorobenzene, hydrazinium nitrate, glicidol, iodine heptafluoride, iodine monochloride, iodine pentafluoride, lead monoxide, mercuric oxide, nitryl fluoride, peroxyformic acid, phosphorus, phosphorus trichloride, tellurium, turpentine, sodium acetylide, sodium peroxide, titanium dioxide. Contact with acetaldehyde may cause polymerization. May form explosive compounds with hexachloroethane, pentachloroethane, picric acid, potassium iodate, potassium peroxide, 2,4,6-trinitrobenzene-1,3,5-triol. 

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