Solid reaction product

If it is desired to carry out the combined operations of stirring, refluxing, and addition of a liquid in a stream of gas, the apparatus of Fig. 77, 7, 12, a may be used the side tube for the gas is sealed on to the separatory funnel. For the passage of a gas into a stirred liquid, the aperture carrying the modified separatory funnel may be fitted with the device shown in Fig. 77, 7, 12, 6 the glass rod inside the tube is held in position by a short length of heavy-wall rubber tubing and is employed to clear the lower end of the gas delivery tube, should it become blocked with solid reaction product. 

The autoclave is cooled to room temperature, and the carbon dioxide is bled off. The solid reaction product is taken from the autoclave, pulverized, and dissolved in 1 1. of water at 50-60°. Ten grams of decolorizing carbon is added, and the mixture is stirred well and filtered to remove cadmium salts and carbon. The filtrate is heated to 80-90° and acidified with concentrated hydrochloric acid to pH 1 (Note 5). 2,6-Naphthalenedicar-boxylic acid precipitates. It is separated from the hot mixture by filtration. It is then suspended in 500 ml. of water at 90-95° (Note 5), separated by filtration, and washed successively with 300 ml. of water, 300 ml. of 50% ethanol, and 300 ml. of 90% ethanol. After being dried at 100-150°/150 mm. in a vacuum oven, the 2,6-naphthalenedicarboxylic acid weighs 42-45 g. (57-61%). It decomposes on a heated block at 310-313°. 

To a well agitated solution of 6.95 grams of 2-amino-6-methyl pyrimidine in 40 cc of pyridine, 15 grams of p-acetylaminobenzenesulfonyl chloride are added in small portions over a 30 minute period. The reaction mixture is then heated on a steam bath for 30 minutes, the free pyridine being then removed under reduced pressure and the residue mixed with cold water, and the latter mixture is vigorously stirred. The solid reaction product is removed by filtration and washed with cold water. 

The study of corrosion is essentially the study of the nature of the metal reaction products (corrosion products) and of their influence on the reaction rate. It is evident that the behaviour of metals and alloys in most practical environments is highly dependent on the solubility, structure, thickness, adhesion, etc. of the solid metal compounds that form during a corrosion reaction. These may be formed naturally by reaction with their environment (during processing of the metal and/or during subsequent exposure) or as a result of some deliberate pretreatment process that is used to produce thicker films or to modify the nature of existing films. The importance of these solid reaction products is due to the fact that they frequently form a kinetic barrier that isolates the metal from its environment and thus controls the rate of the reaction the protection afforded to the metal will, of course, depend on the physical and chemical properties outlined above. 

The behaviour of uranium has been well characterised for a variety of environments of importance in the nuclear industry. The corrosion is governed by the constitution and physical character of the solid reaction products which in turn are determined mainly by the oxygen potential of the environment, the temperature and the presence of water. The mechanisms of attack are known in broad outline. A major area in need of more detailed study is the influence of irradiation both prior to and during oxidation. 

The dissolution of porous minerals, the combustion of porous carbon, the reaction between porous carbon and carbon dioxide, and the formation of nickel carbonyl from pure nickel are some examples of fluid-solid reactions where the reactant solid is porous and where no solid reaction product is formed. A reaction of this type can be represented as... 

The solid reaction product is cooled in ice water and decomposed by addition of an ice-cold solution of 20 g. of potassium carbonate in 250 cc. of water, cooling being continued throughout (Note 6). The mixture is extracted three times with 35-cc. portions of ether the ether extract is dried over calcium chloride and then distilled (Note 7). The ester is obtained from the fraction boiling at 85-98° by fractional distillation by means of a good column (Note 8). The purified ester boils at 95-97° at 740 mm. and weighs 37-45 g. (45-55 per cent of the theoretical amount). 

Perhaps the most straightforward of examinations of the behaviour of plutonium with water was that of Lai and Goya 147) who showed that plutonium metal interacts with seawater to form two types of solid reaction products ... 

Carbon is able to bind sulfur to its surface. The reaction of sugar charcoal or wood charcoal with elementary sulfur at temperatures of 400-1000° was studied in detail by Wibaut (118-122). In this reaction some carbon disulfide was formed as well as hydrogen sulfide, if hydrogen was present in the samples. The solid reaction products contained considerable amounts of sulfur, up to 20% by weight. The maximum sulfur uptake was observed at 600°. The sulfur was not completely volatized even by heating in a vacuum to 1000° (122). The sulfur came off in elementary form and as carbon disulfide. Neither could the sulfur be removed from the samples by extraction. It was disposed of by powerful chemical attack, e.g., by oxidation or by reduction with hydrogen at 700°. The formation of hydrogen sulfide started at 460°. 

For narrow tubes, one must watch out for possible restriction of the tube by solid reaction products, thereby preventing the escape of gaseous products. An explosion may result if this occurs, especially for fast compositions. 

They found that the decomposition of ammonium, iodate starts at 140°C. The reaction yielded a solid reaction product which according... 

Buck, E. C., Fortner, J. A., Bates, J. K., Feng, X., Dietz, N. L., Bradley, C. R. Tani, B. S. 1994. Analytical electron microscopy examination of solid reaction products in long-term tests of SRL 200 waste glasses. In Barkatt, A. Van Konynenbourg, R. A. (eds) Scientific Basis for Nuclear Waste Management XVII. Materials Research Society Symposia Proceedings, 333, 585-593. 

Then the cooled tube is wrapped in aluminum foil except for an area near the bottom of its neck, which is scratched with a glass cutter. The neck is snapped to open the tube, and the solid reaction product is removed and ground in a mortar. The powder is transferred to a 3-L beaker or Erlenmeyer flask and is stirred for 5 h with 1500 mL of deionized water. The mixture is allowed to settle for up to 3 h, then it is filtered through fluted filter paper. The solid residue... 

As-synthesised HMS was prepared using the method prescribed by Tanev and Pinnavaia [1,3]. 0.27 mol of dodecylamine was dissolved in 9.09 mol of ethanol and 29.6 mol of water. 1 mol of TEOS was then added to the mixture under vigorous stirring. The reaction mixture was allowed to age under room temperature for 18 hours. After ageing, the solid reaction product was washed with deionised water and recovered from the aqueous mixture by filtration. The moist solid was subsequently air-dried and sieved into the desired particle sizes using mesh no. 40 (0.425mm) and 60 (0.250mm). Some amount of the as-synthesised HMS sample was then sent for calcination at 630°C for 4 hours. 

Table 15 Some Copper(I) Complexes that Yield Solid Reaction Products With Molecular Oxygen...

How quickly equilibrium is approached is another question. Hemley made his measurements (11) at temperatures of 200°C. and higher, and at 25°C. one will obtain poorly crystallized products. Garrels (5), who has tested similar systems, states that after adding acid or base, pH may return to close to its original value in a matter of hours, even if the solid reaction products are too fine-grained to be identified by x-rays. 

Finally, one more interesting reaction, the mercury-photosensitized polymerization of acetylene should lie mentioned. iShenvood and Gunning (1) showed that a stable mercury compound, probably a mercury carbide, forms in this reaction and that an optimum isotopic composition of 82% 2ll2Hg was obtained in the solid reaction product. These results suggest that, in addition to the primary step leading to the formation of an excited acetylene molecule which was proposed earlier (39), the following two additional primarv routes must also be considered (40) ... 

V-Vinylpyrrolidone 1 (1.00 g, 9.0 mmol) was spread on cylindric glass rings (Raschig coils) in a 500-mL flask and crystallized by cooling to -40 °C in a vacuum. HBr gas (1 bar) was applied for 2h at that temperature. Excess gas was pumped off to a recipient at -196 °C for further use and the solid reaction product 2 was left at room temperature with repeated evacuation for removal of the liberated HBr. The racemic product 3 was recrystallized from acetone to yield 650 mg (65%) of the pure compound (mp 70-73 °C) that was spectroscopically characterized. 

Irradiation of a recrystallized sample (10-15 mg) of 1 through Pyrex in a Ray-onet carousel photoreactor (300 nm) led to clean conversion of the starting material into a single cyclobutane product over the course of 20-50 h. The original colorless crystals visibly yellowed and lost definition around the sharp edges during irradiation but did not shatter or crumble. Treatment of the crude solid reaction product with etherial diazomethane permitted isolation of the cyclobutane product 2b which was shown to have the a-truxillate-type stereochemistry. 

Type II Catalytic Reactions in which Solid Reaction Products Deposit... 

The catalytic reactions which have been studied with the aid of single crystals can be divided into three types for convenience in discussion. Type I includes those reactions in which the surface rearranges to form facets, Type II those in which solid reaction products build up on the surface, and Type III those which apparently leave the surface unaffected. 

Type II Catalytic Reactions in Which Solid Reaction Products Deposit on the Surface the Reaction of Carbon Monoxide on Nickel and Others... 

The precipitate prepared at 80° C. at about the stoichiometric AlEta/TiCE ratio of H has a reddish-brown color, and, according to x-ray analysis, consists of 3-TiCla, whereas the product prepared at 170° C. at the same Al/Ti ratio has a purple color and the structure of 7-TiCE (4, 24, 26). Analysis further showed that the TiCE thus formed contains an appreciable amount of aluminum compounds, and if prepared at 80° C., also some ethyl groups. These aluminum compounds, which apparently consist mainly of A1CE, and possibly of some AEEtCE, are taken up in the crystal lattice of the TiCE since they could not be removed by washing and hardly show up in the x-ray diagram (4, 24). About one out of every six titanium atoms is replaced by aluminum in the 80° C. solid reaction product (4), whereas in the 170° C. product, this... 

This Section focusses on interfacial reactions that cause the formation of dense 3D layers of solid reaction product. It will be assumed that the thickness of the layer is... 

TEM observations of the oxidized scale have revealed mullite grains with transgranular cracks, a phenomenon that is not surprising when one considers that the oxidation of SiC produces a volume expansion of 100%. When the reaction product contains a solid as well as a liquid product, as in the present situation, the volume expansion can be accommodated by squeezing out the liquid phase, resulting in a liquid cap on top of the solid reaction products. This has been observed by Luthra and Park,13 and is apparent in the micrograph shown in Fig. 8.5. 

The transport steps may be controlling either in bringing reactant material to the reaction site (the metal-solution interface) from either phase, or in removing products from the site into the liquid phase,. Accepting the fact that metal reactions in conducting solutions are electrochemical in nature, it follows that control may reside in transport with respect to the cathodic process, or with respect to the anodic process, or with respect to both simultaneously a much less likely possibility. In metal dissolution reactions, the steps can be described still less equivocally for the first case, the transfer of reducible species from the solution to the electrode is involved for the second case, the removal of oxidized species from the electrode is involved. In the latter instance complications are usually caused by the formation of solid reaction products. 

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