HCHO

This kind of dynamieal speetroseopie analysis is not restrieted to fast primary IVR proeesses. It would apply just as well to the sPidy of eompletely unimoleeular reaetions, viz isomerizations sueh as H-atom transfer reaetions, for example CH2O f HCHO [97] HCN f HNC [98],and referenees eited therem), and HCCHf ... 

Physical properties. All colourless. Formaldehyde, HCHO, is a gas, and only its aqueous solution, which has a characteristic pungent odour, is considered metaformaldehyde or trioxymethylene , (CH20)3, is a solid polymer, insoluble in water and ethanol. 

Na PdCl + HCHO + 3NaOH —> Pd -f- HCOONa + 4NaCl + 2HisO... 

Tl Citrate, CE, CN , EDTA, HCHO, hydrazine, NH2OH HCl, oxalate, tartrate, triethanolamine... 

This experiment describes the construction of an air sampler using an aquarium pump, a flow meter, a filter holder, and bottles that serve as traps for analytes. Applications include the determinations of SO2, NO2, HCHO, and suspended particulate matter. 

Formaldehyde, HCHO, is a primary and necessary constituent of the first five synthetic adhesives in the listing. It is a simple organic chemical first identified during the latter half of the 1800s. Its irritating and toxic odor and preservative properties were known from the time of its early development. It is a ubiquitous chemical, formed naturally in small quantities by every process of incomplete combustion as well as in normal biologic processes. The human body has a natural formaldehyde level of about 3 lg/g, ie, 3 parts per million (ppm) in the blood at all times. 

At high enough concentrations, PAN is a potent eye irritant and phytotoxin. On a smoggy day in the Los Angeles area, PAN concentrations are typically 5 to 10 ppb in the rest of the United States PAN concentrations are generally a fraction of a ppb. An important formation route for formaldehyde [50-00-0] HCHO, is reaction 9. However, o2onolysis of olefinic compounds and some other reactions of VOCs can produce HCHO and other aldehydes. 

Aldehydes are important because they are temporary reservoirs of free radicals (see eqs. 11 and 12). HCHO is a known carcinogen. Nitric acid is formed by OH attack on NO2 and by a dark-phase series of reactions initiated by O3 + NO2. Nitric acid is important because it is the second most abundant acid in precipitation. In addition, in southern California it is the major cause of acid fog. 

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