Sulfur dioxide solubility

Oxidation by potassium permanganate is usually carried out in acetic or sulfuric acid solution. Isolation of the sulfone must include separation from the precipitate of manganese(iv) oxide hydrate, which, in the case of sparingly soluble sulfones, is effected by reduction of this precipitate by just sufficient sodium hydrogen sulfite solution or by sulfur dioxide soluble sulfones can be isolated by addition of water after filtration from the hydrated manganese oxide or by acidification and extraction with ether. 

Ammonium sulfate [7783-20-2], (NH 2 U4, is a white, soluble, crystalline salt having a formula wt of 132.14. The crystals have a rhombic stmcture d is 1.769. An important factor in the crystallization of ammonium sulfate is the sensitivity of its crystal habit and size to the presence of other components in the crystallizing solution. If heated in a closed system ammonium sulfate melts at 513 2° C (14) if heated in an open system, the salt begins to decompose at 100°C, giving ammonia and ammonium bisulfate [7803-63-6], NH HSO, which melts at 146.9°C. Above 300°C, decomposition becomes more extensive giving sulfur dioxide, sulfur trioxide, water, and nitrogen, in addition to ammonia. 

Selenium trioxide, SeO, is white, crystalline, and hygroscopic. It can be prepared by the action of sulfur trioxide on potassium selenate or of phosphorous pentoxide on selenic acid. It forms selenic acid when dissolved in water. The pure trioxide is soluble in a number of organic solvents. A solution in Hquid sulfur dioxide is a selenonating agent. It is stable in very dry atmospheres at room temperature and on heating it decomposes first to selenium pentoxide [12293-89-9] and then to selenium dioxide. 

Liquid sulfur dioxide expands by ca 10% when warmed from 20 to 60°C under pressure. Pure liquid sulfur dioxide is a poor conductor of electricity, but high conductivity solutions of some salts in sulfur dioxide can be made (216). Liquid sulfur dioxide is only slightly miscible with water. The gas is soluble to the extent of 36 volumes pet volume of water at 20°C, but it is very soluble (several hundred volumes per volume of solvent) in a number of organic solvents, eg, acetone, other ketones, and formic acid. Sulfur dioxide is less soluble in nonpolar solvents (215,217,218). The use of sulfur dioxide as a solvent and reaction medium has been reviewed (216,219). 

Physical Properties. Sodium metabisulfite (sodium pyrosulfite, sodium bisulfite (a misnomer)), Na2S20, is a white granular or powdered salt (specific gravity 1.48) and is storable when kept dry and protected from air. In the presence of traces of water it develops an odor of sulfur dioxide and in moist air it decomposes with loss of part of its SO2 content and by oxidation to sodium sulfate. Dry sodium metabisulfite is more stable to oxidation than dry sodium sulfite. At low temperatures, sodium metabisulfite forms hydrates with 6 and 7 moles of water. The solubiHty of sodium metabisulfite in water is 39.5 wt % at 20°C, 41.6 wt % at 40°C, and 44.6 wt % at 60°C (340). Sodium metabisulfite is fairly soluble in glycerol and slightly soluble in alcohol. 

Physical Properties. Ammonium thiocyanate [1762-95-4] NH SCN, is a hygroscopic crystalline soHd which deHquesces at high humidities (375,376). It melts at 149°C with partial isomerization to thiourea. It is soluble in water to the extent of 65 wt % at 25°C and 77 wt % at 60°C. It is also soluble to 35 wt % in methanol and 20 wt % in ethanol at 25°C. It is highly soluble in Hquid ammonia and Hquid sulfur dioxide, and moderately soluble in acetonitrile. 

Dilution with water reverses the reaction, and heating the solution Hberates sulfur dioxide. Upon being added to a solution of teUurides, teUurium forms colored polyteUurides. Unlike selenium, teUurium is not soluble in aqueous sodium sulfite. This difference offers a method of separating the two elements. Like selenium, teUurium is soluble in hot alkaline solutions except for ammonium hydroxide solutions. Cooling reverses the reaction. Because teUurium forms solutions of anions, Te , and cations, Te" ", teUurium films can be deposited on inert electrodes of either sign. 

Minor and potential new uses for ammonium thiosulfate include flue-gas desulfurization (76,77), removal of nitrogen oxides and sulfur dioxide from flue gases (78,79), converting sulfur ia hydrocarbons to a water-soluble form (80), and converting cellulose to hydrocarbons (81,82) (see Sulfur REMOVAL AND RECOVERY). 

In many cases, water is a poor scrubbing solvent. Sulfur dioxide, for example, is only slightly soluble in water, so a scrubber of very large liquid capacity would be required. SO2 is readily soluble in an alkaline solution, so scrubbing solutions containing ammonia or amines are used in commercial applications. 

The interactions may be physicochemical without the participation of biological mechanisms for example, deep lung exposure to highly soluble irritative gases, such as sulfur dioxide, may become enhanced due to adsorption of the gas onto fine particles. Biological interactions may occur at all stages and body sites. For example, toxicity is increased when adverse effects are due to some reactive metabolic intermediate and exposure to another agent stimulates its metabolic activation (enzyme induction). 

Reactions between A -(l-chloroalkyl)pyridinium chlorides 33 and amino acids in organic solvents have a low synthetic value because of the low solubility of the amine partner. A special protocol has been designed and tested in order to circumvent this drawback. Soon after the preparation of the salt, an aqueous solution of the amino acid was introduced in the reaction medium and the two-phase system obtained was heated under reflux for several hours. However, this was not too successful because sulfur dioxide, evolved during the preparation of the salt, was converted into sulfite that acted as an 5-nucleophile. As a result, A -(l-sulfonatoalkyl)pyridinium betaines such as 53 were obtained (Section IV,B,3) (97BSB383). To avoid the formation of such betaines, the salts 33 were isolated and reacted with an aqueous solution of L-cysteine (80) to afford thiazolidine-4-carboxylic acids hydrochlorides 81 (60-80% yields). 

Sulfur dioxide is soluble in the electrolyte. Sulfur is soluble up to about 1 mol dm 3, but it precipitates in the cathode pores near the end of discharge. Lithium chloride is essentially insoluble and precipitates on the surfaces of the pores of the carbon cathode, forming an insulating layer which terminates the operation of cathode-limited cells [37],... 

Inert solvents such as dimethyl ether [22], liquid sulfur dioxide or petroleum ether [23] were used to improve the quality of the sulfated alcohol or the reaction conditions. Solvents immiscible in water, such as petroleum ether [24], carbon tetrachloride [25], or butyl alcohol [26], as well as water-soluble sol-... 

R23 is the only significant removal process for N02 and serves as well as a radical sink reaction for HO. Sulfur dioxide (with higher water solubility than NO2.) is also oxidized to sulfuric acid in aerosols and fog droplets (71,72,73,74) its gas-phase oxidation via R24 does not constitute a radical sink, since H02 is regenerated. 

From CS2 solution S7O2 is obtained as intensely orange colored crystals which on heating spontaneously decompose at 60-62 °C with evolution of sulfur dioxide. S7O2 is far less soluble in CS2 (ca. 1 g at 0 °C) than S7O. The solution decomposes within 1 h to a mixture of sulfur homocycles and SO2. Solid S7O2 decomposes at 25 °C within minutes and quantitatively within 2 h, even in the dark. Heating in a high vacuum to 50-60 °C produces S2O and elemental sulfur. The El mass spectrum therefore exhibits peaks due to these decomposition products only [67]. 

Carmines are dehned as the lakes of carminic acid with various metals. The most used is carmine, the aluminium lake of carminic acid. Carmine is not soluble in water or oils and is also very stable under condition of light, heat, oxidation, and sulfur dioxide." ... 

The chlorides of most metals have a very good water solubility, though there are exceptions in the case of some metals. A typical example of the latter is silver which can be very efficiently separated by forming insoluble silver chlorides. Although, the separation of silver as the chloride is rarely used as a method for bulk precipitation, it is certainly useful for the removal of relatively small amounts of the metal when present as a minor constituent In the case of cuprous and cupric chlorides, the former has a low solubility in water hence, if the leach liquor contains cupric chloride, a suitable reducing agent such as sulfur dioxide can be introduced to convert cupric chloride to cuprous chloride so that precipitation occurs. 

Type SR-2 compounds include soluble and reactive gases and vapors which are completely retained in the extrathoracic regions of the respiratory tract. SR-2 compounds include sulfur dioxide (S02) and hydrogen fluoride (HF). 

The alkali-soluble protein of the peel of lemons treated with hydrogen sulfide, sulfur dioxide, and sulfuric acid contained radioactive sulfur, but the fruit treated with hydrogen sulfide had a significantly lower per cent specific activity in the alkali-soluble protein fraction than did the sulfur dioxide or sulfuric acid treated fruits (Table VII). These results suggest that sulfur dioxide and sulfuric acid react with protein more directly, while hydrogen sulfide perhaps must be oxidized first, as indicated in Table III. It also appears (from Table VII) that the alkali-soluble protein may have been dismuted as the amounts isolated were less in both the hydrogen sulfide and sulfur dioxide treated fruit than in the incubated or nonincubated controls. Other evidence of dismutation has been obtained in experiments where incubation at 60° C. was accompanied by the production of free ammonia (18), and the recovery of free ammonia and six amino acids in the exudates of incubated and sulfur-dusted fruits (18). 

Mixtures of the slightly soluble azide with liquid sulfur dioxide became explosive at elevated temperatures. 

Anon., Univ. Safety Assoc., Safety Newsletter, 1982-1984 A solution of the chloride (120 ml) in toluene (750 ml) was treated (apparently without effective stirring) with excess sodium bicarbonate solution to destroy it. When reaction had ceased, the organic layer was poured into a waste solvent drum. Vigorous evolution of sulfur dioxide and hydrogen chloride then ensued from reaction with ethanol (toluene-soluble) in the waste drum. For destruction of solutions of sulfinyl chloride in water-insoluble solvents, extremely good agitation is necessary to ensure proper contact with a basic reagent. Ammonia is more soluble in toluene than is water, so ammonia solution should be used after bicarbonate treatment to ensure complete destruction. 

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