Chemical reactions reaction conditions

An initiative to explore chemical reactions under conditions far removed from normal conditions. Chemical behaviors under extreme pressures, extreme temperatures,... 

Gulaboski R, Mirceski V, Lovric M, Bogeski 1 (2005) Theoretical study of a surface electrode reaction preceded by a homogeneous chemical reaction under conditions of square-wave voltammetry. Electrochem Commun 7 515-522. 

Fig. 16. Log-log of ethylene glycol diacetate yield vs acetic acid concentration when diluted with varying amounts of methyl acetate and water. (Adapted from Ref. 166 with permission. Copyright 1980 American Chemical Society.) Reaction conditions 50-75 ml solvent, 2.35 mmol Ru, 340 atm, H2/CO = 1, 230 C, 2 hr.

Data With respect to the chemical reaction, the conditions in this problem are very similar to those in Example 4.2 except that the concentration of the caustic soda solution here is 0.05M (0.05 kmol/m1) the same physico-chemical data will therefore be assumed, i.e. a second-order rate constant for the reaction... 

Equations 27 and 28 permit a simple comparison to be made between the actual composition of a chemical system in a given state (degree of advancement) and the composition at the equilibrium state. If Q K, the affinity has a positive or negative value, indicating a thermodynamic tendency for spontaneous chemical reaction. Identifying conditions for spontaneous reaction and direction of a chemical reaction under given conditions is, of course, quite commonly applied to chemical thermodynamic principle (the inequality of the second law) in analytical chemistry, natural water chemistry, and chemical industry. Equality of Q and K indicates that the reaction is at chemical equilibrium. For each of several chemical reactions in a closed system there is a corresponding equilibrium constant, K, and reaction quotient, Q. The status of each of the independent reactions is subject to definition by Equations 26-28. 

The pulse induction and existence of the diffusional zone in a chemical reaction are conditions under which the primary physical process is synchronized with the secondary chemical reaction and, therefore, accelerates it. 

Fig. 6.23. Effect of thermal (a) and UV initiation (b), type of comonomer, and percentage of 1-dodecanol in the polymerization mixture on the mode pore diameter of quinidine-functionalized chiral monoliths. (Reprinted with permission from [56]. Copyright 2000 American Chemical Society). Reaction conditions polymerization mixture, chiral monomer 25 8 wt%, glycidyl methacrylate ( ) or 2-hydroxyethyl methacrylate ( ) 16 wt%, ethylene dimethacrylate 16 wt%, porogenic solvent 60 wt% (consisting of 1-dodecanol and cyclohexanol), polymerization time 20 h at 60°C (a) and 16 h at room temperature (b).

Fig. 6.25. Effect of the percentage of 1-propanol in the porogenic mixture on the porous properties of monolithic polymers (Reprinted with permission from [64], Copyright 1998 American Chemical Society). Reaction conditions polymerization mixture ethylene dimethacrylate 16.00 wt.%, butyl methacrylate 23.88 wt.%, 2-acrylamido-2-methyl-l-propanesulfonic acid 0.12 wt.%, ternary porogen solvent 60.00 wt.% (consisting of 10 wt.% water and 90 wt.% of mixtures of 1-propanol and 1,4-butanediol), azobisisobutyronitrile 1 wt.% (with respect to monomers), polymerization time 20 h at 60°C.

Hie most commonly found shape of catalyst particle today is the hollow cylinder. One reason is the convenience of manufacture. In addition there are often a number of distinct process advantages in the use of ring-shaped particles, the most important being enhancement of the chemical reaction under conditions of diffusion control, the larger transverse mixing in packed bed reactors, and the possible significant reduction in pressure drop. It is remarkable (as discussed later) that the last advantage may even take the form of reduced pressure losses and an increased chemical reaction rate per unit reactor volume [11]. 

STiP I The labeled DNA sample is divided into four aubsamples and subjected to four parallel seta of chemical reactions under conditions t hat cause ... 

This chapter develops the thermodynamic methods for predicting whether a reaction is spontaneous, and Chapter 14 uses these results to determine the equilibrium ratio of products and reactants. Chapter 18 discusses the rates of chemical reactions. Manipulating conditions to optimize the yield of chemical reactions in practical applications requires the concepts from all three chapters. 

Chemical Modeling of Metal Adsorption. The second paper of the series (5) addressed the still-unresolved issues of the precise meaning of surface complex and the determination of the potential i[/s. Chemical reactions and conditional equilibrium constants were written out explicitly to describe the average acid-base behavior of a hydroxylated surface, that is,... 

Keywords Green chemistry alternative feedstocks benign reagents catalytic synthetic pathways natural processes biocatalysis alternative solvents safer chemicals alternative reaction conditions minimization of energy consumption... 

Source Reprinted with permission from J. Am. Chem. Soc. 127 (2005) 17171, Table 1. Copyright (2005) American Chemical Society. Reaction conditions solvent acetone/water (4 1), cat. 1 mM, olefin 0.1 M, 50% H2O21 ml, added stepwise by 0.2 ml/0.5 h,... 

It may be tempting to assimilate molecular complexity (complexity of structure) with synthetic complexity (complexity of the synthetic process). However, indices of molecular complexity, even ones such as that described by Bertz, are not equally good as indices of synthetic difficulty. For one thing, there are features such as thermodynamic stability that cannot easily be incorporated into such an index. Also, because each individual feature of structure places constraints on the specific chemical reactions and conditions that may be applied during the time it is present in the synthetic sequence, and because synthetic difficulties may arise through the synergy of certain structural elements, complexity increases nonlinearly with the accumulation of structural elements. In other words, specific combinations of the same structural features can... 

Chemical corrosion, precipitation, and/or undesirable chemical reactions (explosive conditions are an example) are problems using operating conditions for distillation. 

As with many model developments for fouling mechanisms the mathematical analysis is valuable since it draws attention to the salient effects of the variables. The present state-of-the-art models put forward, only go so far towards a complete mathematical solution that may be incorporated in the design of heat exchangers operating under chemical reaction fouling conditions. They are useful however, in suggesting a basis for an empirical formula to correlate experimental data that might so be used. 

Reactors take central place in every production connected with chemical conversion of substances and serve as key elements of technological scheme. Reliability and stability of realized process, its manufacturability, economy and environmental safety depend on perfection of reactors [1, 2], Chemical reactors applied in industry differ in forms it causes troubles with their classification. In particular, it was supposed before that there was no correlation between type of realized chemical reaction and conditions of equipment operation in which this reaction was carried out, but this is not the case. 

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