Silver parting

Another treatment consists of making the silver parts cathode in an alkaline chromate solution. 

We consider a silver electrode covered with a silver chloride film in chloride solution. As shown in Fig. 4—21, the electron level of the silver-silver chloride electrode in ion transfer equilibrium is expressed by the real potential a.(A. A a w) of electrons in the silver part of the electrode as shown in Eqn. 4-27 ... 

Fig. 4-21. Electron energy levels of an ionic electrode of silver-silver chloride in ion transfer equilibrium cfia ) = Fermi level of electron in silver part of electrode snvAfCici-) = equivalent Fermi level to transfer equilibriiun of silver ions and chloride ions in silver-silver chloride electrode.

Although the main routes to propylene oxide formation are not based on direct catalytic oxidation of propylene, the direct epox-idation of propylene on silver would be financially preferable if high yield and selectivity to propylene oxide could be achieved. Similarly to ethylene oxidation on silver part of the undesirable byproduct CO2 comes from the secondary oxidation of propylene oxide (2,3). The kinetics of the secondary silver catalyzed oxidation of propylene oxide to CO2 and H2O have been studied by very few investigators (2). 

Lea MC (1891) On allotropic silver. Part II - relations of allotropic silver with silver as it exists in silver compounds. Am J Sci 141 259-267... 

Alloys of gold or platinum Nitric, chromic and sulfuric and nickel in others Nickel, copper or silver (parting)... 

Jeanmaire D L and Van Duyne R P 1977 Part I heterocyclic, aromatic and aliphatic amines adsorbed on the anodized silver electrode J. Electroanal. Chem. 84 1-20... 

Formaldehyde is a gas, b.p. — 21°, and is usually prepared by the dehydrogenation of methyl alcohol m the presence of heated copper or silver. By admitting air with the methyl alcohol vapour, part of the hydrogen is oxidised to give the heat necessary for the reaction ... 

Sodium anthraquinone-p-sulphonate ( silver salt ). Place 60 g. of fuming sulphuric acid (40-50 per cent. SO3) in a 250 or 500 ml. round-bottomed flask and add 50 g. of dry, finely-powdered anthra-quinone (Section IV,145). Fit an air condenser to the flask and heat the mixture slowly in an oil bath, with occasional shaking, so that at the end of 1 hour the temperature has reached 160°. Allow to cool and pour the warm mixture carefully into a 2 litre beaker containing 500 g. of crushed ice. Boil for about 15 minutes and filter off the unchanged anthraquinone at the pump. Neutralise the hot filtrate with sodium hydroxide and allow to cool, when the greater part of the sodium anthra-quinone-p-sulphonate separates as silvery glistening plates ( silver salt ). Filter these with suction and dry upon filter paper or upon a porous plate. A second crop of crystals may be isolated by concentration of the trate to half the original volume. The yield is 40-45 g. 

The structure of compound A was established in part by converting it to known compounds Treat ment of A with excess methyl iodide in the presence of silver oxide followed by hydrolysis with dilute hydrochlonc acid gave a tnmethyl ether of D galactose Companng this trimethyl ether with known trimethyl ethers of D galactose allowed the structure of compound A to be deduced... 

Aqueous formaldehyde is corrosive to carbon steel, but formaldehyde in the vapor phase is not. AH parts of the manufacturing equipment exposed to hot formaldehyde solutions must be a corrosion-resistant alloy such as type-316 stainless steel. Theoretically, the reactor and upstream equipment can be carbon steel, but in practice alloys are required in this part of the plant to protect the sensitive silver catalyst from metal contamination. 

For the most part, the chemistry of gold is more closely related to that of its horizontal neighbors ia the Periodic Table, platinum and mercury, than to the other members of its subgroup, copper and silver. Comprehensive treatments of gold chemistry can be found ia the Hterature (see General References). 

Metal powder—glass powder—binder mixtures are used to apply conductive (or resistive) coatings to ceramics or metals, especially for printed circuits and electronics parts on ceramic substrates, such as multichip modules. Multiple layers of aluminum nitride [24304-00-5] AIN, or aluminay ceramic are fused with copper sheet and other metals in powdered form. The mixtures are appHed as a paste, paint, or slurry, then fired to fuse the metal and glass to the surface while burning off the binder. Copper, palladium, gold, silver, and many alloys are commonly used. 

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