Polysulfide soluble

HCl-soluble sulfur (pore water sulfates, thiosulfates, polythionates, polysulfides, soluble organic sulfnr, and HCl-hydrolyzable organic sulfur such as sulfate polysaccharides and amino acids)... 

Mercuric Sulfide. Mercuric s A ide[1344 8-5] HgS, exists ia two stable forms. The black cubic tetrahedral form is obtaiaed when soluble mercuric salts and sulfides are mixed the red hexagonal form is found ia nature as cinnabar (vermilion pigment). Both forms are very insoluble in water (see Pigments, inorganic). Red mercuric sulfide is made by heating the black sulfide in a concentrated solution of alkah polysulfide. The exact shade of the pigment varies with concentration, temperature, and time of reaction. 

Soluble sulfides such as sodium sulfide, potassium sulfide, and calcium polysulfides have been used to precipitate mercury salts from alkaline solutions. When this procedure is used, exercise of caution is requked to maintain the pH within a given alkaline range so as to prevent evolution of H2S. Because the solubiUty of mercuric sulfide in water is 12.5 flg/L at 18°C or 10.7 ppb of mercury, use of this method for removal of mercury is adequate for most purposes. However, the presence of excess alkah, such as sodium hydroxide or sodium sulfide, increases the solubiUty of mercuric sulfide as shown ... 

Both the m- and -phenylenediamines are used to manufacture sulfur dyes, either by refluxing in aqueous sodium polysulfide, or heating with elementary sulfur at 330°C to give the leuco form of the dye. These dyes are polymeric, high molecular weight compounds, and soluble in base. The color is developed by oxidation on the fabric. 2,4-Toluenediamine and sulfur give Sulfur Orange 1 (14). 

Sulfur dyes are used for dyeing ceUulosic fibers. They are insoluble in water and are reduced to the water-soluble leuco form for appHcation to the substrate by using sodium sulfide solution. The sulfur dye proper is then formed within the fiber pores by atmospheric oxidation (5). Sulfur dyes constitute an important class of dye for producing cost-effective tertiary shades, especially black, on ceUulosic fibers. One of the most important dyes is Cl Sulfur Black 1 [1326-82-5] (Cl 53185), prepared by heating 2,4-dinitrophenol with sodium polysulfide. 

The monosulfides of the alkaline earth metals crystallize in the rock salt (MgS, CaS, SrS, BaS) and zinc blende (BeS) structures. BaS is insoluble in water, while the other monosulfides are sparingly soluble but hydrolyzed on warming (except MgS that is completely hydrolyzed). The monoselenides are isomorphous to the sulfides. The monotellurides CaTe, SrTe, BaTe adopt the rock salt stmcture, while BeTe has the zinc blende and MgTe the wurtzite structure. Alkaline earth polysulfides may be prepared by boiling a solution or suspension of the metal hydroxide with sulfur, e.g.,... 

Draganjac M, Rauchfuss TB (1985) Transition metal polysulfides Coordination compounds with purely inorganic chelate ligands. Angew Chem Int Ed Engl 24 742-757 DuBois MR (1989) Catalytic applications of transition metal complexes. Chem Rev 89 1-9 Ansari MA, Ibers JA (1990) Soluble selenides and tellurides. Coord Chem Rev 100 223-266... 

Carbon-sulfur hybrid materials, i.e., porous carbons [58,59] or CNTs having nanosized S in the pores or channels, are the most promising solution for the Li-S battery to increase the electronic and ionic conductivity of sulfur or sulfide, and prevent, to a great extent, the solubility of the polysulfide ions formed on reduction of S or upon oxidation of insoluble sulfides [60]. An intimate contact between carbon and sulfur is essential [61]. 

Sulfide minerals were formed mostly hydrothermally from post-magnetic fluids it appears remarkable that the formation of many ore deposits cannot be conclusively explained because of the very low solubility of the corresponding sulfide. Though it was postulated earlier (28, 29, 95) that polysulfido complexes might have been responsible for the transport of metals and sulfur together (80), it was later proved that many discrete polysulfido complexes and clusters of metals exist in polysulfide solutions (see, e.g., 136,138). 

The formation of soluble polysulfido clusters or complexes is also responsible for the fact that some classical analytical separation procedures based on polysulfide solutions (distinguishing between the classical thioanion-forming elements like As, Sb, Sn, and others like Cu) sometimes fail (52). 

Copper(I) sulfide reacts with polysulfide anions in aqueous solutions forming soluble copper polysulfides. 

Colorless crystals or white crystalline mass rapidly deliquesces converts to a yellow rhomhohedral crystalline mass upon exposure to air, forming polysulfides and H2S density 1.68g/cm3 the hemdiydrate loses water at about 175°C melts at 455°C to a dark red hquid decomposes in water soluble in alcohol. 

Sulfur is weakly soluble in H2O (10 M at 298 K) [33, 34], but Na2S is very soluble [35]. In deaerated aqueous solutions, the alkali-metal polysulfide system contains, in addition to H2O and alkali-metal cations, OH , H+, H2S, HS ,... 

The electrochemical behavior of sulfur, sulfide (H8 , S ) and polysulfide ions in water is much less documented than for nonaqueous solvents. Experimental studies are less numerous and do not include a systematic study versus the stoichiometry n of polysulfides M28 . The conclusions of these investigations are often speculative, since the experimental curves do not display strong evidence for chemical species involved in the proposed mechanisms. Moreover, the very low solubility of sulfur in water does not allow the study of its electrochemical reduction in water. 

Equilibrium calculations suggested that Hg complexation varies greatly among redox and pH levels typical of the regions of lakes sampled during this study. In an oxic lake, pore water, and groundwater, Hg complexation with organic matter most likely dominates. Under anoxic conditions in the hypolimnion and pore waters, Hg most likely forms soluble bisulfide and polysulfide complexes. 

The occurrence of sulfide strongly affects the speciation and solubility of numerous trace elements. Solid sulfide phases may be precipitated, and dissolved sulfide and polysulfide complexes may be formed (21-23). The influence of sulfide on trace... 

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