The disulfide is dissolved by aqueous potassium hydroxide, yielding a greenish-yellow solution. At low temperatures no perceptible evolution of gas takes place. Since the disulfide in many respects behaves as a pseudo-halogen, Brown et al. have supposed that the reaction described by Eq. (8) takes place, i.e. a reaction analogous to the formation of halide and halite ions from a halogen and alkali.  [c.273]

When the solution was acidified the disulfide again separated, but the solution also contained the thiol, and, therefore, these investigators supposed that the reaction had proceeded to form an analog not only of a halite but also of a halate [Eq. (9)]. The existence of the  [c.273]

As another example, sylvite (KCl) may be separated from halite (NaCl) by selective flotation in the saturated solutions, using long-chain amines such as a dodecyl ammonium salt. There has been some mystery as to why such similar salts should be separable by so straightforward a reagent. One suggestion has been that since the R—NH3 ion is small enough to fit into a K ion vacancy, but too large to replace the Na ion, the strong surface adsorption in the former case may be due to a kind of isomorphous surface substitution (see Refs. 65,95, and especially 96). Barytes (BaS04) may be separated from unwanted oxides by means of oleic acid as a collector the same is true of calcite (Cap2). Flotation is widely used to separate calcium phosphates from siliceous and carbonate minerals [97].  [c.478]

Halite, see Sodium chloride Hausmannite, see Manganese(II,IV) oxide Heavy hydrogen, see HydrogenpH] or name followed by -d  [c.274]

The common ores of potassium iaclude (/) sylvinite, a mixture of sylvite, KCl, and halite (2) hartsalz, composed of sylvite, haUte, and kieserite [14567-64-7] MgSO 2 anhydrite 5) camaUitite, camaUite [1318-27-0] KCl. MgCl 6H20, and halite (4) langbeinite ore, langbeinite,  [c.245]

Platinum on other valve metals is used where the low critical breakdown potential of titanium presents intolerable limitations. There are several reasons for this in cathodic protection. With good conducting electrolytes, the high anode current densities of on average between 600 and 800 A m, and even up to 10 A m and above, can be made good use of without further problems. With poorly conducting electrolytes (e.g., fresh water) the allowable driving voltage for an economic layout with platinized titanium anodes is not sufficient. In addition, at higher temperatures above about 50°C, the critical breakdown potential decreases still further at 90°C it is about = 2.4 V. Finally, the chemical composition of the electrolyte can influence the breakdown potential. This is for instance the case for acid electrolyte containing hydrogen halites. In such cases materials are chosen as the substrate metal that have properties similar to titanium but are considerably more stable, particularly niobium and tantalum. The breakdown potentials under the limiting conditions described are considerably higher. Driving voltages up to 100 V in chloride solutions are permissible with niobium and tantalum. Platinized niobium and tantalum anodes can be used almost without any limitations. They only break down in electrolytes containing fluoride or boron fluoride, as does titanium, because all three substrate materials cannot form passive films in such media. Niobium has a density of 8.4 g cm and tantalum 16.6 g cm l A further superiority of these valve metals is their high electrical conductivity, which is almost three times that of titanium at 2.4 X 10 cm  [c.216]

Other oxoacid salts of the alkali metals are discussed in later chapters, e.g. borates (p. 205), silicates (p. 347), phosphites and phosphates (p. 510), sulfites, hydrogensulfates, thiosulfates, etc. (p. 706) selenites, selenates, tellurites and tellurates (p. 781), hypohalites, halites, halates and perhalates (p. 853), etc.  [c.90]

ForCb, Bt2 and h, K. c is 4.2 x 10- 7.2 x 10 and 2.0 x 10 mol 1 respectively, thereby favouring the free halogens, whereas Kaik is 7.5 X lO, 2 X lO and 30mol I respectively, indicating a tendency to disproportionation which is overwhelming for CI2 but progressively less pronounced for Br2 and I2. In actuality the situation is somewhat more complicated because of the tendency of the hypohalite ions themselves to disproportionate further to produce the corresponding halite ions  [c.856]

See pages that mention the term Halite : [c.461]    [c.461]    [c.245]    [c.75]    [c.94]    [c.853]    [c.859]    [c.207]   
The Nalco Guide to Cooling Water System Failure Analysis (1993) -- [ c.75 ]