K + 2 reaction

Reaction (13.4) is exothermic and reversible, and begins at about 700 K by Le Chatelier s Principle, more iron is produced higher up the furnace (cooler) than below (hotter). In the hotter region (around 900 K), reaction (13.5) occurs irreversibly, and the iron(II) oxide formed is reduced by the coke [reaction (13.6)] further down. The limestone forms calcium oxide which fuses with earthy material in the ore to give a slag of calcium silicate this floats on the molten iron (which falls to the bottom of the furnace) and can bo run off at intervals. The iron is run off and solidified as pigs —boat-shaped pieces about 40 cm long. 

For weU-defined reaction zones and irreversible, first-order reactions, the relative reaction and transport rates are expressed as the Hatta number, Ha (16). Ha equals (k- / l ) where k- = reaction rate constant, = molecular diffusivity of reactant, and k- = mass-transfer coefficient. Reaction... 

Enzyme catalysis requires that Kj- < Kg. According to transition-state theory (see references at end of chapter), the rate constants for the enzyme-catalyzed k ) and uncatalyzed k reactions can be related to Kg and K by ... 

Catalyst system Molar ratio of the components Reactant Alkene catalyst (mol/mol) Temperature (K) Reaction time Solvent Con- version" (%) Selectivity4 (%) Refer- ence... 

Ag2COa can be prepared in two forms described [757] as active , readily decomposed at 439 K, and inactive , which achieved the same rate of decomposition only at 593 K. Reaction yielded Ag20 and C02 or, at higher temperature (> 520 K) Ag, 02 and C02. 

Barium acetate decomposes [1050] with growth of planar product nuclei, E = 167 kJ mole-1 (720—750 K). Reactions of other Group II acetates are reported [1051] as being accompanied by at least partial melting. 

Kutty and Murthy [1159] have made a kinetic study of the solid—solid reaction between tricalcium phosphate and urea nitrate, a process of possible technological importance. A reduction in particle size, notably of Ca3(P04)2, increased the rate of reaction in powder mixtures and also changed the kinetic characteristics (318—338 K). Reaction in relatively coarse material (between —180 and +200 mesh) obeyed the parabolic... 

Scott, K. Reaction Engineering and Digital Simulation in Electrochemical Processes 27... 

Radius of mass spectrometer A is only 2.5 cm so that very low velocities of the ions (A) can be used. In the collision chamber, k, reaction products (ions B) are formed from the gas by charge exchange or ion-molecule reactions. All ions move in the same direction in the collision chamber and are accelerated by special electrostatic lenses hence, they all reach the slit r of mass spectrometer B (not shown) independently of their initial velocities in the collision chamber. The discrimination in mass spectrometer B can therefore be considered negligible... 

P = polymer of chain length i or J k = reaction rate constant of the step... 

Catalytic reactions were performed in a three-neck flask (about 100 ml) after the catalyst (about 100 mg) was pretreated in a He flow at 573 K. Reactions were... 

Huber et al. 189) have investigated cocondensation (4.2—10 °K) reactions between Ni, Pd and Pt and molecular oxygen in pure O2 and Oj/Ar matrices. These reactions were studied by matrix isolation infra-red spectroscopy, including isotopic and diffusion controlled warm-up studies. They established that both M(02) and (0j)M(02) species were present. The 0-0 bond order suggested significant back-bonding, and this led them to reject the monodentate stmcture. Fig. 8 (b). 

Reaction conditions 10 mmol racemic epichlorohydrin (ECH), 0.7 eq. water, 0.5 mol% R,R-Jacobsen s Co-0 Ac salen catalyst, 120 pi chlorobenzene, 300 K reaction temperature. 

Reaction conditions 10 mmol epichlorohydrin (ECH), 120 p.1 chlorobenzene, 126 p.1 water, 0.02 mol% R,R-Ohgo(cyclooctene) Co-OAc salen catalyst, 300 K reaction temperature. 

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