Chloroethane model

Table 8.3 shows QSAR models between the degradation rate constants of chloroethanes and EHOMO ar d ELUMO under different ozone dosages and UV intensities. Table 8.3 also shows that EHOMO exhibits better correlation with the kinetic rate constants than does Elumo. The correlation increases as the UV intensity increases. Because EHOMO is a measure of the energy necessary... 

UV/H202 oxidation of VOCs has also been studied in detail and several studies reported kinetic models to predict the efficiency of the process. For example, Liao and Gurol [75], Glaze et al. [113], De Laat et al. [155] and Crittenden et al. [74] studied the UV/H202 oxidation of VOCs such as n-chlorobutane, 1,2-dibromo-3-chloropropane and tri- and tetra-chloroethanes in batch photoreactors with low-pressure mercury vapor lamps. Effects of pH, concentration of hydrogen peroxide, UV intensity and the presence of carbonates or fulvic substances were variables studied. 

Chloroethane has a plane of symmetry that passes through the two carbons and the chlorine. The plane is perpendicular to the page in the model and left drawing and is the plane of the page in the right drawing. The hydrogens mirror each other. This compound is not chiral. 

Direct oxidation of the lesser chlorinated ethenes, ethanes, polychlorinated benzenes, and chlorobenzene has been reported. Wiedemeier et al. [25] summarize a number of studies that report direct aerobic oxidation of vinyl chloride (VC), 1,2-dichloroethane, the three dichlorobenzene isomers, 1,2,4-trichlorobenzene, and 1,2,4,5-tetrachlorobenzene. Bradley [33] reports that DCE has served as a primary substrate for energy production with oxygen as the electron acceptor, though use of DCE as a sole carbon source has not been demonstrated. Rittmann and McCarty [29] also report that the two least chlorinated methanes (dichloromethane and chloromethane) as well as chloroethane can be directly oxidized under aerobic conditions. Direct oxidation of the chlorinated compounds is typically modeled using either first-order or Monod kinetics [29,31]. 

Butler and Hayes [28] modeled the rate of abiotic hydrogenolysis of hexa-chloroethane (HCA), 1,1,1-TCA, carbon tetrachloride (CT), and tribromome-thane (TBM) with FeS as a reducing agent using pseudo-first-order kinetics. 

Garrot B., Couderc G., Simonot-Grange M.-H., and Stoeckli F., Co-adsorption of 1,2-dichloroethane and l-bromo,2-chloroethane on zeolite ZSM-5 ftom the liquid and vapour phases, using the Myers-Prausnitz-Dubinin model, Microporous and Mesoporous Materials 52 (2002) pp. 199-206. 

Deactivation of HDC catalysts generally has been ascribed to either interactions between hydrogen chloride (HCl) and the catalyst [7,8] or to coke formation [1-4,9]. To understand the cause(s) of deactivation for this specific reaction and catalyst, the various products observed in the effluent were hydrodechlorinated at 523 K. Results from this study showed that the Pt/ri-alumina catalyst deactivated rapidly during the HDC of 111 TCA and 11 DCA (saturated chlorocarbons containing multiple Cl atoms) and remained stable for the HDC of 11 DCE (unsaturated chlorocarbon), chloroethane (saturated chlorocarbon containing only one Cl atom), and ethylene (unsaturated hydrocarbon). Large quantities of coke were observed on the Pt/rj-alumina after the HDC of 111 TCA, while very little coke was observed on the used catalyst after the HDC of any of the other compoimds. From these experiments, a conceptual model was developed to explain the causes of deactivation, and the reaction sequences that take place with different reactants and catalysts [3,4]. The deactivation of... 

Based on your answers to CTQs 4 and 5, does tyi for the reaction in Model 2 depend on the concentration of chloroethane Explain. 

Draw all possible staggered and eclipsed conformations of l-bromo-2-chloroethane (see the followingball-and-stick model), using Newman projections. Underneath each structure, draw the corresponding dash-wedge and sawhorse structures. Rank the conformations in order of decreasing stability. 

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