Perchlorate magnesium

Other methods for analyzing combustion products can be substituted for chromatography. Gravimetry can be used, for example, after a series of absorption on different beds, as in the case of water absorption in magnesium perchlorate or CO2 in soda lime infra-red spectrometry can be used for the detection of CO2 and water. 

Ammonia, anhydrous Mercury, halogens, hypochlorites, chlorites, chlorine(I) oxide, hydrofluoric acid (anhydrous), hydrogen peroxide, chromium(VI) oxide, nitrogen dioxide, chromyl(VI) chloride, sulflnyl chloride, magnesium perchlorate, peroxodisul-fates, phosphorus pentoxide, acetaldehyde, ethylene oxide, acrolein, gold(III) chloride... 

Dimethylsulfoxide Acyl and aryl halides, boron compounds, bromomethane, nitrogen dioxide, magnesium perchlorate, periodic acid, silver difluoride, sodium hydride, sulfur trioxide... 

Ethylene oxide Acids and bases, alcohols, air, 1,3-nitroaniline, aluminum chloride, aluminum oxide, ammonia, copper, iron chlorides and oxides, magnesium perchlorate, mercaptans, potassium, tin chlorides, alkane thiols... 

Carbonate is measured by evolution of carbon dioxide on treating the sample with sulfuric acid. The gas train should iaclude a silver acetate absorber to remove hydrogen sulfide, a magnesium perchlorate drying unit, and a CO2-absorption bulb. Sulfide is determined by distilling hydrogen sulfide from an acidified slurry of the sample iato an ammoniacal cadmium chloride solution, and titrating the precipitated cadmium sulfide iodimetrically. 

The preferred method of determining water in glycerol is by the Kad Fischer volumetric method (18). Water can also be determined by a special quantitative distillation in which the distilled water is absorbed by anhydrous magnesium perchlorate (19). Other tests such as ash, alkalinity or acidity, sodium chloride, and total organic residue are included in AOCS methods (13,16,18). 

The deterrnination of hydrogen content of an organic compound consists of complete combustion of a known quantity of the material to produce water and carbon dioxide, and deterrnination of the amount of water. The amount of hydrogen present in the initial material is calculated from the amount of water produced. This technique can be performed on macro (0.1—0.2 g), micro (2—10 mg), or submicro (0.02—0.2 mg) scale. Micro deterrninations are the most common. There are many variations of the method of combustion and deterrnination of water (221,222). The oldest and probably most reUable technique for water deterrnination is a gravimetric one where the water is absorbed onto a desiccant, such as magnesium perchlorate. In the macro technique, which is the most accurate, hydrogen content of a compound can be routinely deterrnined to within 0.02%. Instmmental methods, such as gas chromatography (qv) (223) and mass spectrometry (qv) (224), can also be used to determine water of combustion. 

Production of cellulose esters from aromatic acids has not been commercialized because of unfavorable economics. These esters are usually prepared from highly reactive regenerated cellulose, and their physical properties do not differ markedly from cellulose esters prepared from the more readily available aHphatic acids. Benzoate esters have been prepared from regenerated cellulose with benzoyl chloride in pyridine—nitrobenzene (27) or benzene (28). These benzoate esters are soluble in common organic solvents such as acetone or chloroform. Benzoate esters, as well as the nitrochloro-, and methoxy-substituted benzoates, have been prepared from cellulose with the appropriate aromatic acid and chloroacetic anhydride as the impelling agent and magnesium perchlorate as the catalyst (29). 

Magnesium perchlorate (anhydrous). (Available commercially as Dehydrite. Expensive.) Used in desiccators. Unsuitable for drying solvents or any organic material where contact is necessary, because of the danger of EXPLOSION. 

Chemical Designations - Synonyms Anhydione Dehydrite Magnesium perchlorate, anhydrous Magnesium perchlorate, hexahydrate Chemical Formula Mg(C104)2. 

Two absorbents are required, one for water vapour, the other for carbon dioxide. The absorbents for water vapour which are generally employed are (a) anhydrous calcium chloride (14-20 mesh), (b) anhydrous calcium sulphate ( Drierite or Anhydrocel ), and (c) anhydrous magnesium perchlorate ( Anhydrone ). Both (b) and (c) are preferable to (a) (c) absorbs about 50 per cent of its weight of water, but is expensive. Anhydrous calcium chloride usually contains a little free lime, which will absorb carbon dioxide also it is essential to saturate the U-tube containing calcium chloride with dry carbon dioxide for several hours and then to displace the carbon dioxide by a current of pure dry air before use. 

The ground material (40-mesh) is dried in vacuo at room temperature over a desiccant (magnesium perchlorate) that permits practically no water vapor pressure. An assumption was made that at room temperature and in the absence of air, decomposition and oxidation would be negligible. It was found, however, that a direct application of this reference method was not practicable from a routine standpoint, because the time to reach equilibrium was exceedingly long (6 to 9 months). 

Comparison of the results obtained by the redrying procedure with those by the primary reference method (room temperature, in vacuo over magnesium perchlorate) is shown in Table II. The agreement of the two sets of results was within 0.2% or better, which is considered satisfactory and serves to confirm the suitability of the redrying procedure as a secondary reference standard. 

Studies Using Anhydrous Magnesium Perchlorate , G.F. Smith Chem Co, Columbus, O (1935) CA 29,6132 7) M.J. Stross G.B. Zimmer-... 

Can a chiral catalyst containing the same ligand/metal components promote the formation of both enantiomers enantioselectively The bis(oxazoline)magnesium perchlorate-catalyzed asymmetric Diels-Alder reaction [103]... 

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