Solubility zinc sulfide

Sodium sulfide solution or hydrogen sulfide gas are used as the source of sulfide ions. Solutions of Na, Cdi and K+ will not produce precipitates because their sulfides are water soluble. Zinc sulfide (ZnS) is white, while lead(ll) and silver sulfides (PbS and Ag2S) are black. 

Chemical process having the characteristic basing on displacement involves, for example, dissolution of a sulfidic substance in a solution holding a metal ion that yields a less-soluble sulfidic substance. The dissolution of zinc sulfide in copper sulfate solution is a worthwhile example that can be taken in the present context. In analyzing the reaction, reference first is drawn to the final reaction as shown below ... 

In some locations, high-temperature fluids undergo considerable subsurfece mixing with relatively fresh seawater. This leads to precipitation of the less soluble iron and copper sulfides within the conduits. The fluids discharging into the ocean generally have temperatures less than 400°C and are milky white because of zinc sulfide precipitates. These white smokers also build chimneys, some of which are as much as 13 m high. Because of their lower temperatures, white smokers are typically encrusted with worm... 

Zinc sulfide is white to gray-white or pale yellow powder. It exists in two crystalline forms, an alpha (wurtzite) and a beta (sphalerite). The wurtzite form has hexagonal crystal structure refractive index 2.356 density 3.98 g/cm3 melts at 1,700°C practically insoluble in water, about 6.9 mg/L insoluble in alkalis soluble in mineral acids. The sphalerite form arranges in cubic crystalline state refractive index 2.368 density 4.102 g/cm changes to alpha form at 1,020°C practically insoluble in water, 6.5 mg/L soluble in mineral... 

Also, zinc sulfide may be prepared in the laboratory by passing hydrogen sulfide through an aqueous solution of a soluble zinc salt, such as zinc chloride or zinc nitrate. The precipitate is filtered, washed, and dried. 

The cadmium pigments (cadmium-/zinc sulfide and cadmium sulfide/-selenide) are exempted from labelling. The cadmium pigments are slightly soluble in diluted acids and the soluble cadmium is bioavailable. Therefore some cadmium pigment producers are labelling their cadmium-/zinc sulfide and cadmium sulfide/-selenide pigments like the cadmium compounds. 

In the presence of hydrogen sulfide produced by anaerobic bacterial activity, particularly sulfate reducers, conditions are created whereby sulfides of copper and zinc could be formed. The partition of these metals between the sulfide phase and the organic phase depends on the relation between the stability constants of the complexes and the solubility product of the sulfides of these metals. Elements with small solubility products of their sulfides and low stability constants of their chelates would be expected to go into the sulfide phase when hydrogen sulfide is present. Copper is typical of such elements. Chalcocite has a solubility product of about 10" ° and covellite about 10"44, whereas the most stable chelates of copper have stability constants of about 10" Consequently, copper could be expected to be accumulated as the sulfide. Zinc sulfide has a much larger solubility product however, the stability of its chelates is lower. From the fact that zinc appears to be completely associated with the inorganic fraction of coal, it can be assumed that the relation between the solubility product of any of its sulfides and its chelates favors formation of the sulfide. Iron could be expected to follow a similar pattern. 

The paint industry is the largest single consumer of barium compounds. Barium sulfide and zinc sulfate solutions are mixed to give a precipitate of barium sulfate and zinc sulfide, which is heat treated to yield the pigment lithopone. Barium chlorate and nitrate are used in pyrotechnics to impart a green flame. Barium chloride is applied where a soluble barium compound is needed. 

The student should remember from qualitative analysis that white zinc sulfide dissolves readily in dilute HC1, that yellow cadmium sulfide may be dissolved in concentrated HC1, but that black mercuric sulfide (one of the least soluble salts known) requires the action of a trifunctional reagent such as aqua regia (Exercise 1). 

The mercuric compounds, in which mercury is bipositive, differ somewhat in their properties from the corresponding compounds of zinc and cadmium. The differences are due in part to the very strong tendency of the mercuric ion, Hg + +, to form covalent bonds. Thus the covalent nvstal mercuric sulfide, HgS, is far less soluble than cadmium sulfide or zinc sulfide (Chap. 22). 

Dithiophosphoric-0,0-diester with long alkoxy-groups (> 5), optionally with aryloxy-groups, are neutralized in large quantities with zinc oxide to oil-soluble zinc salts and utilized in this form as lubricating oil additives. The zinc dialkyldithiophosphates form a protective layer on metallic materials, which reduces the wear and corrosion of these materials and protects the lubricating oil from oxidation. 96 10 t of zinc dialkyldithiophosphate and other lubricating oil additives on the basis of diphosphorus(V) sulfide were utilized in the USA in 1994. 

Challenge Problem. Zinc sulfide, ZnS, is sparingly soluble under most situations. With ammonia, Zn " " forms four complexes, Zn(NH3)-, Zn(NH3)i+, Zn(NH3)i+, and Zn(NH3)j+. Ammonia is, of course, a base, and S- is the anion of the weak diprotic acid, HiS. Find the molar solubility of zinc sulfide in ... 

In Section 19.3, you saw that H3O increases the solubility of a slightly soluble ionic compound if its anion is that of a weak acid. Similarly, a ligand increases the solubility of a slightly soluble ionic compound if it forms a complex ion with the cation. For example, zinc sulfide is very slightly soluble ... 

Zinc soil chemistry is quite complex in terms of its various combined ionic forms, with zinc being the most readily soluble of all the heavy metals in soils. The major sources of zinc in soils are the zinc sulfide minerals, such as sphalerite and wurtzite, and to a lesser extent minerals such as smithson-ites (ZnCOs), willemite (Zn2Si04), zincite (ZnO), zinkosite (ZnS04) franklinite (ZnPe204) and hopeite (Zn3(P04)2 4H2O). 

Adding ammonium chloride decreases the solubility of aluminum hydroxide and prevents the precipitation of magnesium hydroxide. Scott 13) states that the precipitation of nickel, cobalt, manganese, and zinc sulfides may be incomplete because of the formation of polysulfides in the presence of air or other oxidizing agents. A small amount of ammonium sulfite is therefore added to promote their precipitation. In spite of this precaution, cobalt, nickel, and manganese were never quantitatively recovered and the procedure is not considered entirely satisfactory for these elements. 

Antimony trichloride can be prepared from stibnite, Sb2Ss, the chief ore of antimony. The solubility of this sulfide is intermediate between those of copper sulfide and zinc sulfide, so that it can be precipitated by hydrogen sulfide from 0.3M hydrochloric acid but is easily soluble in 12M hydrochloric acid. 

Zinc is one of the most mobile of the heavy metals. The zinc compounds formed with the common anions found in surface waters are soluble in neutral and acidic conditions. In reducing environments, zinc sulfide (ZnS) is a relatively insoluble and stable compound, which may oxidize in the presence of dissolved oxygen. Zinc carbonate (ZnCOj) is assumed to be less stable than zinc sulfide, though still relatively insoluble. Zinc ions are dominant up to pH values of about 9 in simple aqueous systems. In basic solutions, zinc hydroxide (Zn(OH)2) precipitates if the concentration of zinc is 10.4 M. Zinc hydroxide shows minimal solubility at pH 9.5 and dissolves at higher pH values as the zincate anion, Zn(OH) . 

According to Table 4.2 of the text, zinc ions (Zn ) and sulfide ions (S ) will form an insoluble compound, zinc sulfide (ZnS), while the other product, NaCl, is soluble and remains in solution. This is a precipitation reaction. The balanced molecular equation is ... 

This causes the hydro complex to change into a soluble ammonia complex, the tetramminezincate(II) ion. If the observations in step one and two were caused by Be + or Al, adding ammonium chloride would cause it to reprecipitate as hydroxides due to a lowering of the OH concentrahon (see 3.4. Aluminum). The last step is to add 0.1 ml sodium sulfide solution R, which causes the formation of a white flocculent precipitate of zinc sulfide. 

The mobility of zinc in soil depends on the solubility of the speciated forms of the element and on soil properties such as cation exchange capacity, pH, redox potential, and chemical species present in soil under anaerobic conditions, zinc sulfide is the controlling species (ERA 1980d Kalbasi et al. 

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