Acidic surface area

As the concentration of acid / surface area of magnesium reduces, the slope of the graph lessens and the rate becomes slower. 

This reaction gives high yield of carbon (44-80%) and can be easily scaled. Purifying of the raw material includes treatment of it with sodium carbonate solution with following treatment with acid. Surface area of nanocarbons obtained was 64-500 m2/g, specific electric resistance of powder 0.02-0.07 Ohm.cm. 

Fig. 12. C2HR domain orientations. Each C2HR is labeled with its characteristic tilt (e), roll (r), and swivel (tr), parameters (Deivanayagam et at, 2000) along with the amount of amino acid surface area buried in its domain interface (bs). The C2HRs adopt three distinct D1/D2 orientations. Similar orientations are observed for IL-lORl and 1FNAR2 (group 1), IFN-7RI and TF (group 2), and GHR (group 3). The difference between each group is most obvious if shovm by superimposing the D1 domains of the receptors. (See Color Insert.)...

Table 3 Acidity, Surface Area (SA) and Pore Volume (PV) of fresh catalysts.

Acid-base cooperative effect. Figure 3.38 shows the relationship between the ratio (Sa/Sk) of acidic surface area (Sa) to the basic surface area (Sk) and the... 

AI2O3, Si02 (impurities), and other acidic or amphoteric oxides are the main structural promoters of iron-based catalyst. In the total surface area of catalyst after reduction, in addition to the surface area of basic oxides and metal iron, it should also include the surface occupied by acidic or amphoteric oxides. Subtracting the surface area of metal iron and basic oxides from the total surface area of catalyst results in the surface area of acidic and amphoteric oxides, also known as acid surface area (/Sa), that is,... 

Boffito, D.C., et al., 2013. Ultrasonic enhancement of the acidity, surface area and free fatty acids esterification catal3dic activity of sulphated Zr02—Ti02 systems. Journal of Catalysis 297, 17—26. Available at http //www.sciencedirect.com/science/article/pii/S002195171 2002928 (accessed 22.06.14.). 

Catalytic gas-phase reactions play an important role in many bulk chemical processes, such as in the production of methanol, ammonia, sulfuric acid, and nitric acid. In most processes, the effective area of the catalyst is critically important. Since these reactions take place at surfaces through processes of adsorption and desorption, any alteration of surface area naturally causes a change in the rate of reaction. Industrial catalysts are usually supported on porous materials, since this results in a much larger active area per unit of reactor volume. 

Perhaps the simplest case of reaction of a solid surface is that where the reaction product is continuously removed, as in the dissolving of a soluble salt in water or that of a metal or metal oxide in an acidic solution. This situation is discussed in Section XVII-2 in connection with surface area determination. 

Amorphous carbon, having a far greater effective surface area than either diamond or graphite, is the most reactive form of carbon. It reacts with both hot concentrated sulphuric and hot concentrated nitric acids in the absence of additional oxidising agents but is not attacked by hydrochloric acid. 

Diarrhea is a common problem that is usually self-limiting and of short duration. Increased accumulations of small intestinal and colonic contents are known to be responsible for producing diarrhea. The former may be caused by increased intestinal secretion which may be enterotoxin-induced, eg, cholera and E. col] or hormone and dmg-induced, eg, caffeine, prostaglandins, and laxatives decreased intestinal absorption because of decreased mucosal surface area, mucosal disease, eg, tropical spme, or osmotic deficiency, eg, disaccharidase or lactase deficiency and rapid transit of contents. An increased accumulation of colonic content may be linked to increased colonic secretion owing to hydroxy fatty acid or bile acids, and exudation, eg, inflammatory bowel disease or amebiasis decreased colonic absorption caused by decreased surface area, mucosal disease, and osmotic factors and rapid transit, eg, irritable bowel syndrome. 

Hydrogen Chloride as By-Product from Chemical Processes. Over 90% of the hydrogen chloride produced in the United States is a by-product from various chemical processes. The cmde HCl generated in these processes is generally contaminated with impurities such as unreacted chlorine, organics, chlorinated organics, and entrained catalyst particles. A wide variety of techniques are employed to treat these HCl streams to obtain either anhydrous HCl or hydrochloric acid. Some of the processes in which HCl is produced as a by-product are the manufacture of chlorofluorohydrocarbons, manufacture of aUphatic and aromatic hydrocarbons, production of high surface area siUca (qv), and the manufacture of phosphoric acid [7664-38-2] and esters of phosphoric acid (see Phosphoric acid and phosphates). 

The newly formed y-Mn02 actually coats the surfaces of the particles of the soHd phase the MnSO dissolves in the Hquid phase, along with the majority of the ore impurities. The effective surface area is expanded by the etching action of the sulfuric acid. Following the acid treatment step, the slurry is filtered and the cake is carefiiUy washed and dried at a controlled temperature. 

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