Small scale apparatus advantages

Not all compositions of slush hydrogen are flowable. The maximum solid content for a flowable mixtures appears from early experiments to be just above 50% solid by weight. The calculations in this paper are based on the thermodynamic data P 3] and a flowable mixture of exactly 50% solid to simplify computation, though it is expected that in actual use maximum advantage would be taken of the highest possible solid content. Slush hydrogen with 50% solid has been successfully transferred through tubes in small scale apparatus. 

Skraup reaction, 828, 829, 830, 991, 992 Small scale preparations, 1110-1114 advantages of, 1110, 1111 apparatus for, 1111 basis of an elementary course, 1111-1114... 

For most purposes it is more efficient and convenient to use a compact (short path) distillation apparatus such as that shown in Fig. 11.8. These can be bought, or constructed in two or three convenient sizes to fit the common ground glass joints (see chapter 6 for design details). The main advantage of such devices is that very little material is lost on the sides of the apparatus and joints. Therefore they are particularly appropriate, if not essential, for small scale work. 

Filtration. One of the most convenient aspects of the cannula techniques is that filtration does not require the use of fritted glass equipment. Small scale filtrations are simply carried out by transferring the liquid to be filtered from one Schlenk tube to another through a filter stick as shown in Figure 5. When the filtration is complete the filter paper is discarded, and the cannula washed with acetone to prepare it for the next filtration. The advantages of filter stick filtration over filtration through fritted glass apparatus maybe summarized as follows ... 

When probing the kinetics of a reaction, mnltiple data points (50-100) are required for an accurate comparative Arrhenius plot to be obtained. An advantage of modern small-scale automated microwave apparatus is that it can be used for this very... 

A complete methodology for the manipulation and reaction of air-sensitive solutions has evolved around cappable glass pressure bottles. Soft-drink bottles are sometimes used (hence these procedures are sometimes referred to as pop bottle techniques ) however, heavy-walled borosilicate glass pressure reaction vessels are superior. In contrast to the modified standard taper ware discussed above, this pressure apparatus offers advantages where modest pressures are necessary and where the centrifugation of precipitates is preferable to filtration. These techniques are especially popular in the preparative-scale study of catalytic reactions of small molecules, such as olefin polymerization. The pressure bottle is fitted with a cap containing two 1/8 in. holes and a rubber liner, which is secured by means of a hand-operated bottle capper (Fig. 1.31).18... 

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