C rate constants

Table 5-2. Selected rate constants and half-livese) for some reactions of substituted benzenediazonium ions with buffer solutions (pH 9.00) at 25 °C (rate constants from Virtanen and Kuok-kanen, 1977 half-lives calculated by the present author).

Softener Temperature (°C) Rate constants Unwashed cotton Washed 50 times... 

Entry Enzyme or metal complex with catalase- or peroxidase-like activity pH (T/°C) Rate constant/ M s 1 Refs. 

Catalyst Temperature (°C) Rate constant Order w.r.t ethanol Energy of activation (E = kJ/mol) Ref. 

VP polymer containing 85 mol% of ethylated unit c Rate constant for anionic species... 

Haag, W.R. and Yao, D.C.C. Rate constants for the reaction of hydroxyl radicals with several drinking water contaminants. 

Wahner, A. and Zetsch, C. Rate constants for the addition of hydroxyl radicals to aromatics (benzene, p-chloroaniline, and o, m- and p-dichlorobenzene) and the unimolecular decay of the adduct. Kinetics into a quasi-equilibrium, J. Phys. Chem., 87(24) 4945-4951, 1983. 

Rate constants for the hydrogen abstraction from (Me3Si)3SiH by diaryl aminyl radicals 20-24 were determined by using a method in which the corresponding amines catalyse the reaction of 2,4,6-tri-tert-butylphenoxyl radical with (McsSOjSiH (see below). At 91 °C, rate constants are 33.5, 7.27, 5.63, 2.45 and 45.8 s for radicals 20, 21, 22, 23 and 24, respectively [22]. Based... 

C) Rate constants describe the rate of a reaction as a function of starting concentration(s). A first-order rate constant describes a reaction whose rate depends on the concentration of one component only. A first-order rate constant has units of inverse time (usually s" ). 

Methyl acetate probably originates from the reaction of methanol with the intermediate cobalt-acyl complex. The reaction leading to the formation of acetaldehyde is not well understood. In Equation 8, is shown as the reducing agent however, metal carbonyl hydrides are known to react with metal acyl complexes (20-22). For example, Marko et al. has recently reported on the reaction of ri-butyryl- and isobutyrylcobalt tetracarbonyl complexes with HCo(CO) and ( ). They found that at 25 °C rate constants for the reactions with HCo(CO) are about 30 times larger than those with however, they observed that under hydroformylation conditions, reaction with H is the predominant pathway because of the greater concentration of H and the stronger temperature dependence of its rate constant. The same considerations apply in the case of reductive carbonylation. Additionally, we have found that CH C(0)Co(C0) L (L r PBu, ... 

The data given in Tables IV and V have been plotted in Figures 1 and 2 together with the theoretical curves for the best values of fctra °H and fctransH derived from Equations 21 and 22. The rate constants at 30° and 56°C., respectively, are fctra °H = 600 and 1100 Mole"1 sec."1, ktra°°H = 2500 and 2800 Mole"1 sec."1 (At 56°C. rate constants were obtained from both photoinitiated and AIBN thermally initiated oxidations.) and... 

Figure C. Rate constants for base-catalyzed hydrolysis of Si(acac)z+...

Fig. 21. Catalytic activities of charcoals heated at various temperatures, k = rate constant for o-pHj conversion at —195.8° c — rate constant for H1-D2 exchange at 60°. [Turkevich, J., and Laroche, J., Z. physik. Chem. (Frankfurt) [N.S.] 16, 399 (1958).]...

If an amine P-NH2 is used in the aqueous solution, one obtains RCONHP instead of RCOOH. Rates of cleavage of three acyl nitrophenyl esters were followed by the appearance of p-nitrophenolate ion as reflected by increased absorbances at 400 nm. The reaction was carried out at pH 9.0, in 0.02 M tris(hydroxymethyl)aminomethane buffer, at 25°C. Rate constants were determined from measurements under pseudo-first-order conditions, with the residue molarity of primary amine present in approximately tenfold excess. First-order rate graphs were linear for at least 80% of the reaction. With nitrophenyl acetate and nitrophenyl caproate, the initial ester concentration was 6.66xlO 5M. With nitrophenyl laur-ate at this concentration, aminolysis by polymer was too fast to follow and, therefore, both substrate and amine were diluted tenfold for rate measurements. 

Fig. 10. (a) Relative hydrogenation reactivities of selected aromatic hydrocarbons (CoMoS /Al203, 7.5 MPa, 325°C). Normalized rate constants are shown above the arrows, and equilibrium concentrations at the specified conditions are shown below the compounds (5). (b, facing page) Relative hydrogenation reactivities of selected aromatic hydrocarbons (CoMoS /Al203,69 MPa, 427°C). Rate constants are shown above the arrows, and equilibrium concentrations at 69 and 3.1 MPa are shown below the compounds (35). 

We shall repeat the meaning and dimensions of all the notations Vg—linear velocity of flame propagation relative to the unburned mixture, cm/sec Ki—thermal conductivity at the theoretical temperature of combustion, cal/cm sec deg po—initial density of the mixture, g/cm3 n—concentration of the reacting substance, g/cm3 no—initial concentration of the reacting substance, g/cm3 L—calorific value of the mixture, cal/g To—initial temperature, deg Ti—theoretical temperature of combustion, T — To + L/c, deg E—heat of activation, cal/mole R—gas constant, cal/mole deg C—rate constant of a zero-order reaction, gr/cm3 sec C —rate constant of a first-order reaction, sec- 1 C"—rate constant of a second-order reaction, cm3/g sec. 

Substance Temp. (°C) Rate constants (sec-1) nd3 c2h5od + c2h5ok (In) ... 

Fig. 5-8. Correlation oilgik/kf) [35] and the cohesive pressure <5 [238] in the Diels-Alder dimerization of cyclopentadiene at 40 °C (rate constants relative to acetone as slowest solvent) ...

Fig. 5-11. Correlation between % k/kf) [59, 64] and the Kirkwood function (sr — l)/(2fir + 1) for the Menschutkin reaction between triethylamine and iodoethane in 32 aprotic and dipolar aprotic solvents at 25 °C (rate constants relative to n-hexane as slowest solvent) ...

TABLE 25. Relative at 53.2°C rate constants for the exchange reaction of RD in MeONa/MeOH... 

Figure 11.10. Rate constants for reactions of ozone and OH radicals with solutes, (a, b) Examples of rate constants for direct reactions of ozone with organic and inorganic solutes versus pH (data selected), is related to k by the yield factor, (c) Rate constants for reactions of OH radicals with different solutes. (A03)37 is the required amount of decomposed ozone, which results in the elimination of the quoted substrate to 37% of the initial value (batch-type or plug-flow reactor). This scale is calibrated for eutrophic lakewater (Lac de Bret, DOC = 4 mg liter"[HCOf] = 1.6 mM, pH = 8.3. The latter changes proportionally to the DOC of water). (From Hoignd, 1988.)...

Trinuclear [W3S4(H20)9]4+ reacts with Cu metal with the formation of green, air-sensitive [W3CuS4(H2O)10]5+, UV-vis peaks A(nm) (e(M-1cm-1)) at 288(5,500), 384(1,940), 570 (342).338 No 4+ W3CuS4 core is known. On addition of Cu1 to [M3S4(H20)9]4+ (M = Mo, W) the kinetics indicate first-order dependencies for each reactant, with Cu+ attachment to one S atom occurring in the rate-limiting step. At 25 °C, rate constant M s1 are 980 (Mo), 1,820 (W).338 Subsequent reorientation and attachment to other i—S core atoms occurs. In the case of Mo, a second Cu+ independent step is observed. 

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