Stoichiometry, determining

In agreement with previous suggestions [9], the present results have confirmed that whatever be the nature of the cation or of the heteroatom, the acidic salts appeared in the form of pure acid embedded in a neutral salt. The conditions of precipitation and more particularly the initial stoichiometry determine the texture and the composition of the resulting precipitate. 

During the last decade capillary electrophoresis (CE) has become a mature separation technique for pharmaceutical analysis. Numerous validated methods from pharmaceutical R D lahoratories and academia have been reported in literature, including identity confirmation, main component assay, purity determination, enantiomeric separation, and stoichiometry determination. In addition, CE is frequently applied as an orthogonal technique during the development of stability indicating liquid chromatography methods. As a result CE... 

The stoichiometry determines the ratios of lithium aluminum hydride to other compounds to be reduced. Esters or tertiary amides treated with one hydride equivalent (one fourth of a molecule) of lithium aluminum hydride are reduced to the stage of aldehydes (or their nitrogen analogs). In order to reduce an ester to the corresponding alcohol, two hydride equivalents, i.e. 0.5 mol of lithium aluminum hydride, is needed since, after the reduction of the carbonyl, hydrogenolysis requires one more hydride equivalent. 

The highly crosslinked nature of the polymer formed in the discharge is immediately apparent from the C,j spectrum which exhibits approximately equal quantities of the four major carbon environments CFj, CF, CF and carbon with four nearest carbon neighbors. The overall stoichiometry determined from a comparison of the F,5 and Ci peak intensities is reported to be CiFi.4. The amount of oxygen functionalities found in these polymers, due to reaction of free radical sites in the polymer with atmospheric oxidants is usually less than 0.1 atomic % and is observed in the ESCA spectrum as a small broad signal in the 0, region . ... 

T. Schmidt, G. Schiitz, H. Gruber and H. Schindler, Local stoichiometries determined by counting individual molecules, Anal. Chem. 68, 4397 (1996). 

Figure 5 Stoichiometry determination for the system MBP-VLDLR2-3/HRV2. The plot was derived from the CE separations shown in Figure 4. (Reprinted from Ref. 22.)...

The results confirm previous suggestions based upon approximate stoichiometry determinations using conventional precipitation experiments that at sufficiently low supersaturation HAP can precipitate without the need for precursor formation both at the surface seed crystals (6)and spontaneously from solution (56). 

So far we have discussed the rate of this reaction only in terms of the reactant. The rate can also be defined in terms of the products. However, in doing so, we must take into account the coefficients in the balanced equation for the reaction, because the stoichiometry determines the relative rates of the consumption of reactants and the generation of products. For example, in the reaction... 

To form double-stranded poly(A)-poly(U), equimolar amounts of the two homopolymers are mixed at a concentration of 0.6-1.5 fiM nucleotide (about 200-500 /iig/ml) in 0.1 A/ NaCl, 0.01 M phosphate pH 7 at room temperature and allowed to anneal for a few hours. Hypochromicity occurs at 260 nm when a double helix is formed and at both 260 and 280 nm when a triple helix is formed. At room temperature and 0.1 Af NaCl, only the stoichiometry determines which helix will form. At high ionic strength (0.7 M NaCl), and at high temperature, even a 1 1 mixture will form a triple helix with time triple-strand formation is also favored by... 

Stoichiometric The characteristic proportions of chemical reaction, obtained from chemical formulae, equations, atomic weights and molecular weights. Stoichiometry determines what and how much is used and produced in a chemical process. 

Figure 6 Stoichiometry-driven self-assembly reagent stoichiometry determines the average length of the...

The molar mass of glueose is 180.15 g mol". From this, we ean ealculate the number of moles of glucose formed and, using the reaction stoichiometry, determine the number of moles of CO2 needed. With that information and the other information provided in the problem, we ean use the ideal gas law to ealculate the volume of air that is needed ... 

EXPERIMENT 5.4 ELECTRON TRANSFER REACTION BETWEEN [CO(en)3]2+ AND [Co(ox)2(en)]-—STOICHIOMETRY DETERMINATION USING ION-EXCHANGE CHROMATOGRAPHY11... 

Results Summary for the Stoichiometry Determination of the Electron Transfer Reaction between [Co(en)3]2+ and [Co(ox)2(en)] ... 

See the Saunders Interactive General Chemistry CD-ROM, Screen 5.8, Using Stoichiometry Determination of an Empirical Formula. 

Reactors Determine reaction stoichiometry. Determine equilibrium yield. Measure catalyst selectivity, activity, and lifetime. Identify and characterize reaction byproducts. Determine kinetics of major side reactions. Determine effects of recycle. 

Stoichiometries determined (a) for O2 /substrate reactions by titration of excess (Me4N)O2 (with voltammetric detection) (b) for released Br and Cl by titration with AgNOj for released O2 by negative-scan voltammetry and (c) for organic products by ether extractions and capillary-column gas chromatography. 

Substitution of these y, and " expressions into the B R transfer coefficients [Eq. (1)] immediately demonstrates the equivalence of the derivations. Although, practically speaking, it is difficult to imagine examples where the stoichiometry-determining step would be far separated from the rds, we believe that the expanded transfer coefficients derived here are expressed in a fashion that is more directly relevant to their use in determining mechanism. 

The stoichiometry determines the product. Thallium(III) chloride reacts similarly, but only the bis(organo)thallium chloride is formed. Thallium(III) chloride also reacts with... 

The stoichiometry determines the product. Thallium(III) chloride reacts similarly, but... 

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