Sulfur reaction with zinc

Iron(III) sulfate may be reduced to +2 oxidation state of the metal in solution in the presence of common reducing agents. For example, reaction with zinc in sulfuric acid can produce iron(II) sulfate. The molecular equation is as follows ... 

Reaction with Zinc dust and Sulfuric Acid... 

In the actual process (Figure 10-5), the natural gas feedstock must first be desulfurized in order to prevent catalyst poisoning or deactivation. The desulfurization step depends upon the nature of the sulfur-containing contaminants and can vary from the more simple ambient temperature adsorption of the sulfur-containing materials on activated charcoal to a more complex high-temperature reaction with zinc oxide to catalytic hydrogenation followed by zinc oxide treatment. 

Summary Hydrogen gas is easily prepared by reacting hydrochloric acid or sulfuric acid with zinc or aluminum, or by reacting lye with aluminum foil. If using hydrochloric acid or sulfuric acid, avoid metal foils or finely divided metals such as aluminum foil, or zinc dust, as the reaction will be quite violent. For aluminum, aluminum pop cans house the best source, as they are cheap and readily available. 

An old way of producing hydrogen gas in the laboratory was by the reaction of sulfuric acid with zinc metal... 

Problem Diluted acids can dissolve base metals and produce hydrogen and a salt solution. In the case of the reaction of magnesium with dilute sulfuric acid, hydrogen and magnesium sulfate solution are produced. Concentrated acids dissolve a metal too however no hydrogen is formed. In the reaction of concentrated sulfuric acid with zinc, the gas hydrogen sulfide is produced which has a rotten-egg smell. It is therefore important, in the case of sulfuric acid to differentiate between the pure acid from the diluted acidic solution and should be labeled carefully. Both reactions are not acid-base reactions - they are redox reactions (see Chap. 8). 

Classification Inorganic zinc salt Definition Reaction prod, of sulfuric acid with zinc avail, commercially as the monohydrate avail, as the heptahydrate, mainly for laboratory purposes Empincal 04SZn Formula ZnS04... 

Cholesterol occurs in most biological materials in both the free and esterified forms. Quantitative determination of cholesterol is based on color reactions, which are not absolutely specific but suffice since cholesterol is the predominating sterol in most materials. The color reactions include the Liebermann-Burchard reaction with sulfuric acid and acetic acid anhydride, the Tschugaeff reaction with zinc chloride and acetyl chloride in acetic acid, or the Lifschiitz reaction with ferric chloride in acetic acid and sulfuric acid. Both free and esterified cholesterol participate in these reactions. Methods for the determination of cholesterol which are commonly used are those of Schoenheimer and Sperry (1934), Sperry and Webb (1950), Zak et al. (1951), Zlatkis et al. (1953). They were recently reviewed by Vanzetti (1964). 

The only RR-based antioxidants are reaction products of sulfur or phosphorus pentasulfide with - terpenes (ot-pinene), resin oils and unsaturated esters. Reaction of alcohols (Cg) with phoshorus pentasulfide, followed by a reaction with zinc oxide yields salts of dialkyl dithiophosphoric acid (ZDDP), which are widely used, not only as antioxidants but also as corrosion inhibitors and extreme-pressure additives. Longer-chain alcohols enhance oil solubility. 

Various sulfides of the halogens are formed by direct combination of sulfur with fluorine, bromine, and chlorine. No evident reaction occurs with iodine instead, the elements remain as components of a mixture. Mixtures of sulfur and potassium chlorate, or sulfur and powdered zinc, are highly explosive. 

Oxidizing elements such as oxygen, sulfur, and halides react with zinc at room temperature in the presence of moisture, but do not in its absence. At higher temperature, the reactions can be vigorous even when dry. Eor instance, a powdered mixture of zinc and sulfur explodes if warmed and zinc reacts... 

Arsine is formed when any inorganic arsenic-bearing material is brought in contact with zinc and sulfuric acid. The arsenides of the electropositive metals are decomposed with the formation of arsine by water or acid. Calcium arsenide [12255-53-7] Ca2As2, treated with water gives a 14% yield of arsine. Better yields (60—90%) are obtained by decomposing a solution of sodium arsenide [12044-25-6] Na As, in Hquid ammonia with ammonium bromide (14,15). Arsine may be accidentally formed by the reaction of arsenic impurities in commercial acids stored in metal tanks, so that a test should be made for... 

Dithionites. Although the free-dithionous acid, H2S2O4, has never been isolated, the salts of the acid, in particular zinc [7779-86-4] and sodium dithionite [7775-14-6] have been prepared and are widely used as industrial reducing agents. The dithionite salts can be prepared by the reaction of sodium formate with sodium hydroxide and sulfur dioxide or by the reduction of sulfites, bisulfites, and sulfur dioxide with metallic substances such as zinc, iron, or zinc or sodium amalgams, or by electrolytic reduction (147). 

Tsai et al. have also used RAIR to investigate reactions occurring between rubber compounds and plasma polymerized acetylene primers deposited onto steel substrates [12J. Because of the complexities involved in using actual rubber formulations, RAIR was used to examine primed steel substrates after reaction with a model rubber compound consisting of squalene (100 parts per hundred or phr), zinc oxide (10 phr), carbon black (10 phr), sulfur (5 phr), stearic acid (2 phr). 

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. 

Tnfluoromethanesulfinate can be prepared from the reaction of trifluoromethyl bromide with sulfur dioxide and zinc [50] (equation 41) Similar insertion occurs when perfluoroalkyl iodides are used as precursors (equations 41 and 42)... 

Zinc and cadmium tarnish quickly in moist air and combine with oxygen, sulfur, phosphorus and the halogens on being heated. Mercury also reacts with these elements, except phosphorus and its reaction with oxygen was of considerable practical importance in the early work of J. Priestley and A. L. Lavoisier on oxygen (p. 601). The reaction only becomes appreciable at temperatures of about 350° C, but above about 400°C HgO decomposes back into the elements. 

Reduction with zinc dust in aqueous sulfuric acid gives 2-methyl-4-aminothiophenol (28) Condensation with 2-chlorobenzoic acid (Ullmann reaction) leads to 29, which can close to but one thiox-anthone (25) on treatment with sulfuric acid. Although this procedure is longer than the original, the yields are good and the sequence is regioselective. ... 

Sulfur reacts very slowly with rubber, and so is compounded with rubber in the presence of accelerators and activators. Typical accelerators are thia-zoles and a typical activator is a mixture of zinc oxide and a fatty acid. The chemistry of the vulcanisation reactions is complicated, but generates a three-dimensional network in which rubber molecules are connected by short chains of sulfur atoms, with an average of about five atoms in each chain. 

Reactions of zinc-copper reagents bearing acidic hydrogen and sulfur functionalities with various electrophiles, including nitroalkenes, have been reported, as shown in Eq. 4.86108 and Eq. 4.87,109 respectively. 

Polychloroprene rubbers are not efficiently vulcanized by sulfur. The chlorine atoms deactivate the double bonds toward reaction with sulfur. Vulcanization is achieved by heating with zinc and magnesium oxides. Crosslinking involves the loss of... 

The resulting products, such as sulfenic acid or sulfur dioxide, are reactive and induce an acid-catalyzed breakdown of hydroperoxides. The important role of intermediate molecular sulfur has been reported [68-72]. Zinc (or other metal) forms a precipitate composed of ZnO and ZnS04. The decomposition of ROOH by dialkyl thiophosphates is an autocata-lytic process. The interaction of ROOH with zinc dialkyl thiophosphate gives rise to free radicals, due to which this reaction accelerates oxidation of hydrocarbons, excites CL during oxidation of ethylbenzene, and intensifies the consumption of acceptors, e.g., stable nitroxyl radicals [68], The induction period is often absent because of the rapid formation of intermediates, and the kinetics of decomposition is described by a simple bimolecular kinetic equation... 

The most significant parent structure for pigments of this group is obtained by a slightly modified route by simply using phthalic anhydride instead of aldehyde. Reaction with m-diethylaminophenol at 180°C in the presence of sulfuric acid or zinc chloride and subsequent oxidation with iron(III)chloride thus affords a dye known as Rhodamine B (132), the basis of Pigment Violet 1 ... 

A( ueous solutions of chromium(ll) sulfate have Ijeen prepared from chromium(lll) sulfate by reduction with zinc powder and from potassium dichromate by reduction with amalgamated zinc and sulfuric acid. Solid chromitim(II) sulfate penlahyrlrate can be obtained from the reaction of highly purified chromium metal... 

Yu and Bailey (1992) studied the reaction of nitrobenzene with four sulfide minerals under anaerobic conditions. Observed half-lives of nitrobenzene were 7.5, 40, 105, and 360 h for the reaction with sodium sulfide, alabandite (manganese sulfide), sphalerite (zinc sulfide), and molybdenite (molybdenum sulfide), respectively. Aniline and elemental sulfur were found as reduction products of nitrobenzene-manganese sulfide reaction. Aniline was also a reduction product in the nitrobenzene-molybdenum sulfide and nitrobenzene-sodium sulfide reactions. Several unidentified products formed in the reaction of nitrobenzene and sphalerite (Yu and Bailey, 1992). 

---