Experimental order

Related to the preceding is the classification with respect to oidei. In the power law rate equation / = /cC C, the exponent to which any particular reactant concentration is raised is called the order p or q with respect to that substance, and the sum of the exponents p + q is the order of the reaction. At times the order is identical with the molecularity, but there are many reactions with experimental orders of zero or fractions or negative numbers. Complex reactions may not conform to any power law. Thus, there are reactions of ... 

Which ylide is more easily formed in this way Is your result in accord with the experimental ordering of reactivity Is this the ylide with the more negative carbon ... 

Of course the calculations can be improved by adding extra terms until this failure is eventually corrected. However, these additional measures are only taken after the facts are known. In addition, the lengths to which theoreticians are forced to go to in order to obtain the correct experimental ordering of terms... 

It may be seen that in both cases, the predicted values follow the experimental order. Also, it may be seen that the variation of % and r with the... 

Monte Carlo and Molecular Dynamics simulations of water near hydrophobic surfaces have yielded a wealth of information about the structure, thermodynamics and transport properties of interfacial water. In particular, they have demonstrated the presence of molecular layering and density oscillations which extend many Angstroms away from the surfaces. These oscillations have recently been verified experimentally. Ordered dipolar orientations and reduced dipole relaxation times are observed in most of the simulations, indicating that interfacial water is not a uniform dielectric continuum. Reduced dipole relaxation times near the surfaces indicate that interfacial water experiences hindered rotation. The majority of simulation results indicate that water near hydrophobic surfaces exhibits fewer hydrogen bonds than water near the midplane. 

Nevertheless, when other solvents were studied, no total consistency is observed between the magnitude of the equilibrium constants and the experimental order in... 

However, experimental studies of the effect upon thiophene or thienothiophenes 1 and 2 of phenyl radicals obtained by thermal decomposition of iV-nitrosoacetanilide, or from aniline and amyl nitrite, demonstrated a somewhat different experimental order of reactivity thieno[3,2-6]thiophene (2) > thiophene > thieno[2,3-6]thiophene (1). It was also found that the phenyl radical preferentially attacks position 2... 

The experimental scheme for a three level reflected saturated fractional design for seven factors is shown in Table 5.15 ( note that one factor was retained as a dummy factor to be used as an additional error check). The experimental order of the scheme was sorted on acid type as this required long equilibration times, this ordering loses some of the features of the initial design but is a compromise that can be justified on the fact that... 

A second change was made to the experimental order in that the initial experimental conditions were run first not last as recommended in the Plackett-Burman scheme. This is again a practical compromise as it allows the analyst to check the instrumental set-up with well-established conditions. 

The experimental order of this study was also changed from the ideal randomised and blocked design. This was justified for reasons of automation where column changes needed to be minimised. As for the aspirin study the validity of this compromise depends on the fact that the repeatability of the method, over a time span such as that required for the ruggedness test, had previously been established. 

As for radical substitutions in compounds XV, XVII, XXV, and some other compounds, the F values (hence also Ar and Sr values, cf. section V, A) correctly predict the experimental reactivity order. The calculated and experimental orders disagree in the case of compounds XXI and, particularly, XVI the latter case (radical phenylation of quinoline) represents a serious failure of the theory, for the experimental study was very thorough.160 It is worth noting that in the compounds which have no meso-position the center of radical reactivity is the position adjacent to the nitrogen atom (with the exception of the just mentioned phenylation of quinoline). 

Other results also confirm the important role of internal diffusion. Experimental activation energies (67—75 kJ mol"1) of the sucrose inversion catalysed by ion exchangers [506—509] were considerably lower than those of a homogeneously catalysed reaction (105—121 kJ mol"1) [505, 506,508] and were close to the arithmetic average of the activation energy for the chemical reaction and for the diffusion in pores. The dependence of the rate coefficient on the concentration in the resin of functional groups in the H+-form was found to be of an order lower than unity. A theoretical analysis based on the Wheeler—Thiele model for a reaction coupled with intraparticle diffusion in a spherical bead revealed [510,511] that the dependence of the experimental rate coefficient on acid group concentration should be close to those found experimentally (orders, 0.65 and 0.53 for neutralisation with Na+ and K+ ions respectively [511] or 0.5 with Na+ ions [510]). 

Below the critical (Curie) temperature, Tc a ferromagnet spontaneously magnetizes to a permanent magnet whose magnitude and direction is denoted by the magnetization vector, M(T). The experimental order parameter is defined by ... 

The experimental orders were 0.66 and 1.02, respectively, in excellent agreement with the electrochemical model. Another mathematical consequence of this model is a marked change in the kinetic orders when one of the products of the reaction is added to the initial mixture [238]. Thus if hexacyanofer-rate(II) (commonly called ferrocyanide and abbreviated Feoc) is present at the start of the reaction, the theory forecasts that the order with respect to Feic and I- will increase to 2 and 3, respectively, while the order with respect to Feoc will be — 2. In the event, a plot of lnecat versus ln[Feoc] was a curve that coincided with a line of slope - 2 at the higher concentrations of ferrocyanide. At a constant initial Feoc concentration of 4 x 10 4 mol dm 3,... 

Molecular Stabilities. Bauer noted that the shorter N=N distance in cw-N2F2 is entirely compatible with the greater thermochemical stability of the cw-N2F2. The order of N—F dissociation energies is also compatible with the order of their calculated overlap populations. Our calculated total energies for cis- and trans-N2F2 confirm the experimental order of thermal stabilities. 

Several features of the vibrational spectrum of 1 are characteristic also for its heterocyclic analogues, such as oxirane and aziridine. Komornicki and coworkers showed that the three ring molecules have six types of internal coordinates in common (CH stretch, CH2 deformation, CH2 twist, CH2 rock, CH2 wag and ring motions see Figure 20). The experimental order for the CH stretching motions of 1 is 3102 cm ), v,2 3082 cm ), v,... 

While there is abundant evidence from magnetic and ESR data, as well as from electronic spectroscopy (Section 4), to support qualitatively the d-orbital splittings predicted by the simple CF model for cubic complexes, the model is clearly inadequate. Electrostatic calculations of Ao fail to account for the experimental order of magnitude, and sometimes even the sign An even more serious objection is raised by experimental evidence suggesting that a purely ionic description of the bonding in transition-element compounds is inappropriate. 

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