Mass yields

Assemble in a fume-cupboard the apparatus shown in Fig. 67(A). Place 15 g. of 3,5-dinitrobenzoic acid and 17 g. of phosphorus pentachloride in the flask C, and heat the mixture in an oil-bath for hours. Then reverse the condenser as shown in Fig. 67(B), but replace the calcium chloride tube by a tube leading to a water-pump, the neck of the reaction-flask C being closed with a rubber stopper. Now distil off the phosphorus oxychloride under reduced pressure by heating the flask C in an oil-bath initially at 25-30, increasing this temperature ultimately to 110°. Then cool the flask, when the crude 3,5-dinitro-benzoyl chloride will solidify to a brown crystalline mass. Yield, 16 g., i.e,y almost theoretical. Recrystallise from caibon tetrachloride. The chloride is obtained as colourless crystals, m.p. 66-68°, Yield, 13 g Further recrystallisation of small quantities can be performed using petrol (b.p. 40-60°). The chloride is stable almost indefinitely if kept in a calcium chloride desiccator. 

Thus for batch crystallizations the mass yields and heat loads are given by ... 

In any quantitative assessment of growth and/or product formation, it is essential to link formation of microbial biomass and products with the utilisation of substrate and nutrients. In the case of microbial biomass production, the total amount of cell mass yield formed is often proportional to the mass of substrate utilised. Mathematically this is coefficient expressed as the corresponding ratio, or yield coefficient ... 

This example expresses all the performance measures on a molar basis. The mass yield of l,4-dimethyl-2,3-dichlorobenzene sounds a bit better. It is 0.541 lb of the desired product per pound of xylene charged. 

Review a recent synthetic reaction you have carried out in the laboratory. Write a balanced equation for the reaction(s) and calculate the atom economy. From your experimental results calculate the Yield, E-factor and Effective Mass Yield (ignoring any water used). Identify ways in which this reaction could be made greener. 

The high atomic mass yields small recoil energies and thus a large recoU-free fraction even at room temperature (/300 0.95 for Ta metal [175]) this allows measurements of the resonance effect to be made over a wide temperature range up to about 2,300 K. 

Neoprene (C4H5CI) is burned in air at constant pressure with the reactants and products at 25 °C. The mass yields of some species are found by measurement in terms of g/gp. These product yields are CO at 0.1, soot (taken as pure carbon, C) at 0.1 and gaseous unbumed hydrocarbons (represented as benzene, CgHg) at 0.03. The remaining products are water as a gas, carbon dioxide and gaseous hydrogen chloride (HC1). 

Where 7, represents the fractional mass yield of z in the z-rich product. 

Eq. 5.17 when written in terms of number average molar mass yields ... 

Preliminary bonding studies [11] to dentin treated with 3-methoxy-PIDAA or 2-carboxy-PIDAA (0.1 mol/L in aqueous acetone 1 1 mass) yielded composite to dentin mean shear bond strength values of 26.4 MPa ( 4.5 MPa) and 21.0 MPa ( 5.4 MPa), respectively, similar to the PIDAA control value of 24.2 MPa ( 6.7 MPa), where represents standard uncertainity in these measurements. 

A variety of diseases can affect bone and its structure. Paget s disease, for example, is a disorder arising from abnormal osteoclasts, characterized by exeessive bone resorption followed by replacement of the normal mineralized bone with structurally weak, poorly mineralized tissue. However, the most important bone disease is osteoporosis. This is a skeletal bone disease characterized hy microarchitectural deterioration of bony tissue and loss of bone mass, yielding increased susceptibility to bone fracture and bone fragility. In the United States, osteoporosis results in 1.5 million hone fractures annually, with 250,000 of these being hip fractures that sometimes ultimately culminate in patient death. There is a variety of therapies for the prevention and treatment of osteoporosis. 

The volume occupied by the solid plus the volume of voids when divided into the powder mass yields the bulk density. Therefore, when powder is poured into a graduated container, the bulk density is the mass divided by the volume of the powder bed. 

Dividing the gram molecular mass you were given (194.2 g/mol) by this empirical formula mass yields the quotient, 2. Multiplying each of the subscripts in the empirical formula by 2 produces the molecular formula, CgHjgN 02. The common name for this culturally important compound is caffeine. 

Several other metrics include effective mass yield, atom economy, mass intensity, mass productivity, and reaction mass efficiency, which are defined by Equations 3.2-3.6. 

The consecutive reactions have been investigated by the method of preparative voltammetry, namely by analyzing the product mixture, which is essentially composed of the anodic monomer and dimer independence of working potential or current density resp. Correlating the respective current and mass yields of monomers and dimers with current density allows the kinetic laws governing the selectivities at different anode materials to be obtained. 

Figure 1 shows some of the single fallout particles collected after the Chinese nuclear explosion on May 14, 1965 (14). Figure 2 shows the mass-yield distribution of the fission products in some of the single fallout particles (5). The values of H calculated in this manner range from 30-50 sec., as shown in Table 1(4). 

Figure 2. Mass-yield distribution of the fission products in single fallout particles collected at Osaka, Japan and Fayetteville, Ark. after the May 9, 1966 Chinese nuclear explosion (4)...

The curves show the general shape of the 235U fission mass-yield curve. The yields at masses 89, 91, and 140 are down because of their gaseous and volatile precursors (see text). The yields at masses 103 and 129 are also low owing to the volatile prop-ties of the elements Ru and Te... 

Just as earlier we were able to observe mass-yield distributions of the fission products from the fissionable nuclide used in the Chinese nuclear device, it is possible to see part of the mass-yield curve from the fission of 244Pu, which was synthesized originally in a supernova. Figure 6 shows the mass-yield distribution of the excess fissiogenic xenon observed in the meteorite Pasamonte (15). 

Figure 6. Mass-yield distribution of the fissiogenic xenon isotopes in the meteorite Pasamonte (15)...

Methyl (9,V,12S)-12-[(Benzyloxycarbonyl)(niethyl)aniino]-5-bromo-16,17-dichloro-7-niethoxy-10-niethyl-4,11-dioxo-2-oxa-10-azatricyclo[12.2.2.r, 7]nonadeca-l(16),3(19),5,14,17-pentaene-9-carboxylate (15) [l6 A soln of 14 (8.0 g, 10.7 mmol) in MeOH (5.5 L) at 4 °C was treated with TTN (14.3 g, 32.2 mmol). The mixture was stirred at 4 °C for 18 h. Pyridine (15 mL) was added, and the mixture was concentrated in vacuo. The residue was diluted with brine and extracted with EtOAc. The combined organic layers were washed with sat. aq Na2S203 and brine, dried (MgS04), and concentrated in vacuo. Chromatography (silica gel, hexane/EtOAc gradient 3 1—1 1) afforded 15 as a colorless, amorphous mass yield 380 mg (5%) [a]D29 —120.6 (c 0.45, CHC13) and 16 as a colorless, amorphous mass yield 1.0 g (14%) [a]D29 -170.8 (c 0.69, CHC13). 

More recently, the fed-batch biotransformation of / -ionone by Aspergillus niger was described [126]. A commercially available strain, A. niger IFO 8541 was selected and was found to be an efficient biocatalyst for the biotransformation of / -ionone into 2- and 4-hydroxy-/ -ionone and 2-oxo-/ -ionone. 4-Hydroxy-/ -ionone was the main product with a mass yield close to 90%. It is interesting to note that the metabolism of / -ionone involves a lag phase, which is a function of the... 

Figure 11.15 Schematic representation of the mass yield distributions for the spontaneous fission of the trans-berkelium nuclides. (From D. C. Hoffman, et al., Spontaneous Fission in Nuclear Decay Modes, D. N. Poenaru, Ed. Copyright 1996 IOP Press. Reprinted by permission of IOP Press.)...

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