Iodides hydrogen sulfide

Chemical Properties. The most significant chemical property of L-ascorbic acid is its reversible oxidation to dehydro-L-ascorbic acid. Dehydro-L-ascorbic acid has been prepared by uv irradiation and by oxidation with air and charcoal, halogens, ferric chloride, hydrogen peroxide, 2,6-dichlorophenolindophenol, neutral potassium permanganate, selenium oxide, and many other compounds. Dehydro-L-ascorbic acid has been reduced to L-ascorbic acid by hydrogen iodide, hydrogen sulfide, 1,4-dithiothreitol (l,4-dimercapto-2,3-butanediol), and the like (33). 

Potassium chromate Potassium iodide Hydrogen sulfide gas Disodium hydrogen phosphate Sodium carbonate... 

Hydroiodic acid, the colorless solution formed when hydrogen iodide gas dissolves in water, is prepared by reaction of iodine with hydrogen sulfide or hydrazine or by an electrolytic method. Typically commercial hydroiodic acid contains 40—55% HI. Hydroiodic acid is used in the preparation of iodides and many organic iodo compounds. 

The iodate is a poison potassium iodide, however, is used in foodstuffs. Thus the iodate must be completely removed frequently by a final reduction with carbon. After re-solution in water, further purification is carried out before recrystallization. Iron, barium, carbonate, and hydrogen sulfide are used to effect precipitation of sulfates and heavy metals. 

Typical brines received at an Arkansas bromine plant have 3—5 g/L bromide, 200—250 g/L chloride, 0.15—0.20 g/L ammonia, 0.1—0.3 g/L hydrogen sulfide, 0.01—0.02 g/L iodide, and additionally may contain some dissolved organics, including natural gas and cmde oil. The bromide-containing brine is first treated to remove natural gas, cmde oil, and hydrogen sulfide prior to introduction into the contact tower (48). 

Ethylene imine Hydrazine hydrate Hydrogen sulfide. Hydroxylamme salts Inorganic Hg. compounds lodates Iodides... 

First, mention should be made of the metathetical reaction, replacing an anion of a pyrylium salt by another-, when the solubility of the latter salt is lower than that of the former, the conversion is easy. In the opposite case, one has to find a solvent in which the solubilities are reversed (perchlorates are less soluble in water than chloroferrates or iodides, but in concentrated hydrochloric or hydroidic acids, respectively, the situation is reversed For preparing chlorides which are usually readily soluble salts, one can treat the less soluble chloroferrates with hydrogen sulfide or hydroxylamine. Another method is to obtain the pseudo base in an organic solvent and to treat it with an anhydrous acid. 

The alkyl chain distribution of the base alcohol in alcohol sulfates is easily determined by gas chromatography. However, alcohol sulfates and alcohol ether sulfates are not volatile and require a previous hydrolysis to yield the free alcohol. The extracted free alcohol can be injected directly [306] or converted to its trimethylsilyl derivative before injection [307]. Alternatively, the alcohol sulfate can be decomposed by hydroiodic acid to yield the alkyl iodides of the starting alcohols [308]. A preferred method forms the alkyl iodides after hydrolysis of the alcohol sulfate which are analyzed after further extraction of the free alcohol, thus avoiding the formation of hydrogen sulfide. This latter method is commonly used to determine the alkyl chain distribution of alcohol ether sulfates. 

The Iodometric method has also been utilized in analyzing hydrogen sulfide in the air (EPA 1978). The method is based on the oxidation of hydrogen sulfide by absorption of the gas sample in an impinger containing a standardized solution of iodine and potassium iodide. This solution will also oxidize sulfur dioxide. The Iodometric method is suitable for occupational settings. The accuracy of the method is approximately 0.50 ppm hydrogen sulfide for a 30-L air sample (EPA 1978). 

Hydrogen iodide, or Hydrogen selenide, or Hydrogen sulfide See Non-metal hydrides, below... 

Flow injection analysis has been used for the automated determination of hydrogen sulfide in seawater [20]. A low-sensitivity flow injection analysis manifold for concentrations up to 200 imol/l hydrogen sulfide had a detection limit of 0.12 xmol/l. Sulfide standards were calibrated by colorimetric measurement of the excess tri-iodide ion remaining after reaction of sulfide with iodine. The coefficient of variation was less than 1% at concentrations greater than 10 imol/l. The method was fast, accurate, sensitive enough for most natural waters, and could be used both for discrete and continuous analysis. 

A dramatic departure of ozone measurements from total oxidant measurements has b Mi reported for the Houston, Texas, area. Side-by-side measurements suggested that either method was a poor predictor of the other. Consideration was given to known interferences due to oxides of nitrogen, sulfur dioxide, or hydrogen sulfide, and the deviations still could not be accounted for. In the worst case, the ozone measurements exceeded the national ambient air quality standard for 3 h, and the potassium iodide instrument read less than 15 ppb for the 24-h period. Sulfur dioxide was measured at 0.01-0.04 ppm throughout the day. Even for a 1 1 molar influence of sulfur dioxide, this could not explain the low oxidant values. Regression analysis was carried out to support the conclusion that the ozone concentration is often much higher than the nonozone oxidant concentration. 

A similar reaction occurs with bromine at first copper(ll) bromide is formed which at red heat converts to copper(I) bromide. Fluorination yields CuF2. Heating the metal with iodine and concentrated hydriodic acid produces copper(l) iodide. When copper is heated in an atmosphere of hydrogen sulfide and hydrogen, the product is copper(I) sulfide, CU2S. 

Nitrogen dioxide oxidizes an aqueous solution of iodide to iodine, hydrogen sulfide to sulfur, and carbon monoxide to carbon dioxide. In such reaction, it is reduced to nitric oxide, rather than nitrogen ... 

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