Sulfur dioxide chemical reactions

Substituted benzenesulfonamides bearing strongly electron-attracting substituents can be reduced in slightly alkaline solution at the dropping mercury electrode to ammonia, sulfur dioxide, and a substituted benzene (Chapter 23). Saccharin is a compound of this type, and the primary electrode reaction is a cleavage of the carbon-sulfur bond chemical reactions follow the initial cleavage. 

Production of a-methylstyrene (AMS) from cumene by dehydrogenation was practiced commercially by Dow until 1977. It is now produced as a by-product in the production of phenol and acetone from cumene. Cumene is manufactured by alkylation of benzene with propylene. In the phenol—acetone process, cumene is oxidized in the Hquid phase thermally to cumene hydroperoxide. The hydroperoxide is spHt into phenol and acetone by a cleavage reaction catalyzed by sulfur dioxide. Up to 2% of the cumene is converted to a-methylstyrene. Phenol and acetone are large-volume chemicals and the supply of the by-product a-methylstyrene is weU in excess of its demand. Producers are forced to hydrogenate it back to cumene for recycle to the phenol—acetone plant. Estimated plant capacities of the U.S. producers of a-methylstyrene are Hsted in Table 13 (80). 

Whereas sulfolane is relatively stable to about 220°C, above that temperature it starts to break down, presumably to sulfur dioxide and a polymeric material. Sulfolane, also stable in the presence of various chemical substances as shown in Table 2 (2), is relatively inert except toward sulfur and aluminum chloride. Despite this relative chemical inertness, sulfolane does undergo certain reactions, for example, halogenations, ting cleavage by alkah metals, ring additions catalyzed by alkah metals, reaction with Grignard reagents, and formation of weak chemical complexes. 

Production. Sulfolane is produced domestically by the Phillips Chemical Company (Borger, Texas). Industrially, sulfolane is synthesized by hydrogenating 3-sulfolene [77-79-2] (2,5-dihydrothiophene-l,1-dioxide) (2), the reaction product of butadiene and sulfur dioxide ... 

Chemical Properties. Thionyl chloride chemistry has been reviewed (169—173). Significant inorganic reactions of thionyl chloride include its reactions with sulfur trioxide to form pyrosulfuryl chloride and with hydrogen bromide to form thionyl bromide [507-16-4]. With many metal oxides it forms the corresponding metal chloride plus sulfur dioxide and therefore affords a convenient means for preparing anhydrous metal chlorides. 

Titanium Sulfates. Solutions of titanous sulfate [10343-61-0] ate readily made by reduction of titanium(IV) sulfate ia sulfuric acid solutioa by electrolytic or chemical means, eg, by reduction with ziac, ziac amalgam, or chromium (IT) chloride. The reaction is the basis of the most used titrimetric procedure for the determination of titanium. Titanous sulfate solutions are violet and, unless protected, can slowly oxidize ia coatact with the atmosphere. If all the titanium has been reduced to the trivalent form and the solution is then evaporated, crystals of an acid sulfate 3 Ti2(S0 2 [10343-61-0] ate produced. This purple salt, stable ia air at aormal temperatures, dissolves ia water to give a stable violet solutioa. Whea heated ia air, it decomposes to Ti02, water, sulfuric acid, and sulfur dioxide. 

Sulfur Dioxide EPA Method 6 is the reference method for determining emissions of sulfur dioxide (SO9) from stationary sources. As the gas goes through the sampling apparatus (see Fig. 25-33), the sulfuric acid mist and sulfur trioxide are removed, the SO9 is removed by a chemical reaction with a hydrogen peroxide solution, and, finally, the sample gas volume is measured. Upon completion of the rim, the sulfuric acid mist and sulfur trioxide are discarded, and the collected material containing the SO9 is recovered for analysis at the laboratory. The concentration of SO9 in the sample is determined by a titration method. 

Although it does not physically explain the nature of the removal process, deposition velocity has been used to account for removal due to impaction with vegetation near the surface or for chemical reactions with the surface. McMahon and Denison (12) gave many deposition velocities in their review paper. Examples (in cm s ) are sulfur dioxide, 0.5-1.2 ozone, 0.1-2.0 iodine, 0.7-2.8 and carbon dioxide, negligible. 

Sulfur dioxide emissions may affect building stone and ferrous and nonferrous metals. Sulfurous acid, formed from the reaction of sulfur dioxide with moisture, accelerates the corrosion of iron, steel, and zinc. Sulfur oxides react with copper to produce the green patina of copper sulfate on the surface of the copper. Acids in the form of gases, aerosols, or precipitation may chemically erode building materials such as marble, limestone, and dolomite. Of particular concern is the chemical erosion of historical monuments and works of art. Sulfurous and sulfuric acids formed from sulfur dioxide and sulfur trioxide when they react with moisture may also damage paper and leather. 

Fluorinated sulflnates are prepared from sodium dithionite and liquid per-fluoroalkyl halides [74] (equation 67). For the transformation of the gaseous and poorly reactive trifluoromethyl bromide, it is necessary to use moderate pressure [75] (equation 68) These reactions are interpreted by a SET between the intermediate sulfur dioxide radical anion and the halide The sodium trifluorometh-anesulfinate thus obtained is an intermediate for a chemical synthesis of triflic acid. 

The chemical reactions appear simple. They begin with pure sulfur (which occurs in natural deposits in the elemental state). First, sulfur is burned to give gaseous sulfur dioxide, S02. Next, the S02 is further oxidized, catalytically, to sulfur trioxide, SO ,. Finally, addition of water forms sulfuric acid. The reactions are ... 

X 10 4 M HCl(aq) with phenolphthalein indicator to see how much NaOH was left unreacted. They found that 30.2 mL of HCl(aq) was required to reach the stoichiometric point, (a) Write the balanced chemical equation for the reaction of S02 and water, (b) What amount of NaOH (in mol) had reacted with the SO, (c) What was the concentration of sulfur dioxide in the air, in parts per million ... 

The sulfur dioxide reacts with more hydrogen sulfide to give elemental sulfur and water. Write balanced chemical equations for these two reactions, and determine the minimum mass of hydrogen sulfide that a volcano must emit in order to deposit 1.25 kg of sulfiir. 

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