Silver chloride oxide

Bronze disease necessitates immediate action to halt the process and remove the cause. For a long time, stabilization was sought by removal of the cuprous chloride by immersing the object in a solution of sodium sesquicarbonate. This process was, however, extremely time-consuming, frequentiy unsuccesshil, and often the cause of unpleasant discolorations of the patina. Objects affected by bronze disease are mostiy treated by immersion in, or surface appHcation of, 1 H-henzotriazole [95-14-7] C H N, a corrosion inhibitor for copper. A localized treatment is the excavation of cuprous chloride from the affected area until bare metal is obtained, followed by appHcation of moist, freshly precipitated silver oxide which serves to stabilize the chloride by formation of silver chloride. Subsequent storage in very dry conditions is generally recommended to prevent recurrence. 

As shown in equation 12, the chemistry of this developer s oxidation and decomposition has been found to be less simple than first envisioned. One oxidation product, tetramethyl succinic acid (18), is not found under normal circumstances. Instead, the products are the a-hydroxyacid (20) and the a-ketoacid (22). When silver bromide is the oxidant, only the two-electron oxidation and hydrolysis occur to give (20). When silver chloride is the oxidant, a four-electron oxidation can occur to give (22). In model experiments the hydroxyacid was not converted to the keto acid. Therefore, it seemed that the two-electron intermediate triketone hydrate (19) in the presence of a stronger oxidant would reduce more silver, possibly involving a species such as (21) as a likely reactive intermediate. This mechanism was verified experimentally, using a controlled, constant electrochemical potential. At potentials like that of silver chloride, four electrons were used at lower potentials only two were used (104). 

Chlor-siure, /. chloric acid. -sMureanhydrid, n. chloric anhydride, chlorine(V) oxide, -schwefel, n. sulfur chloride (esp. the monochloride). -silber, n. silver chloride, -sili-cium, n. silicon tetrachloride, -soda, /. = Chlornatron. -stickstoff, m. nitrogen chloride. -Strom, m. stream of chlorine, -strontium, n. strontium chloride, -suifonsaure, /. chlorosulfonic acid, chlorosulfuric acid, -toluol, n. chlorotoluene. -fibertrager, m. chlorine carrier. 

The precipitate is curdy (compare silver chloride) and is readily coagulated by boiling. It is washed with dilute ammonium thiocyanate solution a little sulphurous acid or ammonium hydrogensulphite is added to the wash solution to prevent any oxidation of the copper)I) salt. 

Generally, such a remarkable restriction of metal dissolution results not only from the formation of a thin surface oxide film but also from the formation of a comparatively thick film such as silver chloride or zinc chloride. In this chapter, however, we use the term passive film only for compact and thin oxide films. 

A catalytic version of the coupling was also developed, by using 10 mol % of CuCl2 and 20 mol % of sparteine 1 (silver chloride was used as a stoichiometric oxidant to regenerate the copper (II) oxidant). This catalytic system was applied to the asymmetric cross-coupling leading to 101 in a 41% yield and 32% ee. 

In alkaline solutions, sometimes the cadmium-cadmium oxide RE is used its design is the same as that of the silver-silver chloride RE (a thin layer of cadmium oxide is formed on the surface of metallic cadmium). This electrode is quite simple to make and manipulate, but its potential is not very stable E = +0.013 V. 

In individnal cases, anodic polarization of metals in electrolyte solntions will pro-dnce snrface layers (adsorbed or phase) which instead of oxygen, contain the soln-tion anions. Thns, anodic polarization of silver in chloride-containing solntions yields a snrface layer of silver chloride, while the anodic polarization of lead in snl-fnric acid solntion yields a lead sulfate layer. Layers of sulhdes, phosphates, and other salts can be formed in the same way. In many respects the properties of such salt layers are analogous to those of the oxide layers. 

Silver bromide Silver chloride Silver perchlorate Silver cyanide Silver fluoride Silver iodide Silver permar>gate Silver nitrate Silver carbonate Silver oxide Silver sulphate Silver sulphide Silver phosphate... 

Chemical precipitations which are not dependent on pH are used in various processes. Sometimes the reagent is reasonably set for a certain metal and this is the situation in the precipitation of silver as silver chloride. The only other insoluble common metal chlorides of significance are lead chloride, cuprous chloride, and mercurous chloride. This implies that precipitation of cuprous and mercurous chlorides generally may be avoided by ensuring that the metals occur in their higher oxidation states, cupric and mercuric states. The separation of silver in its chloride form is rarely employed for bulk precipitation, but is quite useful for removing relatively small amounts of the metal when it occurs in minor amounts. 

The possibility of the oxidation of Cl and SCN ions were also examined. 10 ml of 500 ppm neutral FeCl3 solution was sonicated for 30 min, while the control sample was kept for the same duration in the atmospheric condition. These sonicated and controlled samples were treated with AgN03 to precipitate unaffected remaining amount of chloride ions as silver chloride. The amount of precipitable chloride was same in both sonicated as well as unsonicated solutions. Similarly, the reappearance of pink colour in the sonicated and decolourised solution of I e(SC )6]3 upon the addition of FeCl3 confirmed that the SCN- too did not oxidize during the decomposition and decolourisation of the complex but remained unaffected even after the complex had perished. 

It melts without decomposition although the enthalpy of conversion to silver chloride and oxygen appears to be about —0.5 kJ/g. An explosion while grinding the salt (which had not been in contact with organic materials) has been reported [1]. A powerful oxidant. 

See Gold(III) chloride Ammonia Mercury Ammonia Potassium triamidothallate ammoniate Silver azide Ammonia Silver chloride Ammonia Silver nitrate Ammonia Silver(I) oxide Ammonia See N-METAL DERIVATIVES... 

It was observed in those cases in which the oxidation was arrested too soon that an appreciable amount of silver chloride was deposited when the solution was concentrated. Furthermore, the mother liquor, when treated with phenyl-hydrazine in acetic acid, deposited some yellow crystalline D,L-mannose phenylhydrazone, m. p. 195-200° (Maquenne block). It is apparent that too vigorous oxidation results in the formation of hexoses. 

Both ways have been used in previously reported attempts to remove chloride interference. Three methods have been used in attempts to prevent chloride oxidation masking with mercury (II) [191,192] precipitation of chloride using silver (I) [188] or altering oxidation conditions [193]. 

Silver chloride is the oxidized form, so we write it on top of the bracketed fraction, and silver metal is the reduced form, so we write it beneath. But we must also write a term for the chloride ion, because Cl- (aq) appears in the balanced reduction reaction in Equation (7.42). 

The stoichiometric oxidative coupling of various phenols proceeds with moderate selectivity (76% ee) in the presence of (-)-sparteine CuCl2, Eq. 106 (127). As mentioned above, selectivity seems to be driven by solubility issues since isolation of the product from the precipitate or from solution results in different enantiose-lectivities. Indeed, this system performs far worse under catalytic conditions. The best result involves the use of silver chloride as reoxidant the heterooxidative coupling of two naphthols 182 and 183 affords the product 184 in 41% yield and 32% ee using 10 mol% catalyst, Eq. 107. 

Electrochemical oxidation-reduction of eluting mixture components is the basis for amperometric electrochemical detectors. The three electrodes needed for the detection, the working (indicator) electrode, reference electrode, and auxiliary electrode, are either inserted into the flow stream or imbedded in the wall of the flow stream. See Figure 13.13. The indicator electrode is typically glassy carbon, platinum, or gold, the reference electrode a silver-silver chloride electrode, and the auxiliary a stainless steel electrode. Most often, the indicator electrode is polarized to cause oxidation of the mixture components... 

The preparation of dichloroacetone by the following methods is described in the literature the direct chlorination of acetone 1 the oxidation of dichlorohydrin 2 the action of silver chloride on diiodoacetone 3 the action of dichloropropene (CH2CI— CC1 = CH2) and hypochlorous acid 4 the action of hydrochloric acid on ethoxymonochloroacetoacetic ester 5 and the hydrolytic cleavage of dichloroacetoacetic ester.6... 

B. 2-(4-Methoxyphenyl)-2-cyclohexen-1-one. A 500-mL, round-bottomed flask, equipped with a 1.5-in. Teflon-coated magnetic stirring bar and an argon inlet adaptor, is charged with 10.02 g (45.1 mmol) of 2-iodo-2-cyclohexen-1-one, 10.69 g (70.4 mmol, 1.56 eq) of 4-methoxyphenylboronic acid (Note 8), 16.72 g (72.1 mmol, 1.6 eq) of silver(l) oxide (Ag20) (Note 9), 0.85 g (2.8 mmol, 6 mol %) of triphenylarsine (Note 10), 0.53 g (1.4 mmol, 3 mol %) of palladium(ll) bis(benzonitrile)dichloride (Note 11), 200 mL of tetrahydrofuran (THF) and 25 mL of water (Note 12). The reaction mixture, flushed with argon, is stirred for 1 hr and then quenched by the addition of 125 mL of saturated aqueous ammonium chloride. After the solution is stirred for 1 hr, the... 

Rhenium tetrachloride oxide, 4167 Rhodium(III) chloride, 4155 Rhodium tetrafluoride, 4349 Ruthenium(III) chloride, 4156 Silver chloride, 0008... 

A chiral dinuclear Ti(IV) oxide 20 has been successfully designed by Maruoka and coworkers and can be used for the strong activation of aldehydes, thereby allowing a new catalytic enantioselective allylation of aldehydes with allyltributyltin (Scheme 12.18). ° The chiral catalyst 20 can be readily prepared either by treatment of bis(triisopropoxy)titanium oxide [(/-Pr0)3Ti-0-Ti(0/-Pr)3] with (S)-BINOL or by the reaction of ((5)-binaphthoxy)isopropoxytitanium chloride with silver(I) oxide. The reaction of 3-phenylpropanal with allyltributyltin (1.1 equiv) under the influence of 20 (10 mol%) gives l-phenyl-5-hexen-3-ol... 

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