Molar absorptivity average values

With the aid of the molar absorptivity value of 31600 at pH 10, as given by Fry (13), we have determined the feruloylester content of the four pectins. These are quite different (Table I). Acid-soluble and alkali-soluble pectins contain many more feruloylester groups on average one such group per pectin molecule. It is tempting to presume a relationship between feruloylester content and ease of extraction of the pectins, but this requires further study. 

Using this relation, a molar absorptivity of the order of 10 has been calculated for the average organic molecule with an assumed cross-section of about 10 cm and a unit transition probability. The highest values known for e are a few hundred thousand any value above 10,000 is considered high, and one under 1000 low. 

Here, i]ppp indicates the luminescence efficiency of the donor, n is the refractive index, Aem, > is the normalized emission spectrum of the donor in the absence of acceptor species, A hs.D corresponds to the absorption spectrum of the acceptor (more precisely, the molar decadic extinction coefficient of the acceptor), v is the frequency wavenumber and k is a factor related to the orientation of the donor and the acceptor dipole moments, k is of the order of unity, and an average value of k = 2/3 is used most of the time, corresponding to dipole moments that are randomly distributed over all orientations. While... 

CifPractice Problem B Referring to Practice Problem A, (a) determine the absorbance values you would expect for solutions with the following concentrations 0.4 M, 0.6 M, 0.8 M, 1.1 M (b) Using the data in the table in Practice Problem A, calculate the average molar absorptivity of the compound and determine the units of molar absorptivity. 

F = 0.508. The concentration of protein is F X A280 = (0.508 X 0.69) mg/mL = 0.35 mg/mL. Note the table applies to mixtures of proteins, such as might be found in a crude cellular extract, and reflects the absorption properties of average proteins. For a purified protein, the values of F would have to be altered to reflect the unique molar extinction coefficient of that protein. 

The rate at which a compound is transformed by direct photolysis will be determined by the rate at which radiation is absorbed by that compound that will be determined, in turn, by the radiation available, Z, and the absorption of that radiation by the compound. The absorption of quinoline in the solar range is defined by the extinction coefficients (Table 6.9). Note that average molar extinction coefficients correspond to the wavelength range of Z and kJ.X) values can be calculated for... 

Often the term A is called the absorption factor and S the stripping factor, where S = /A. These equations can be used with any consistent set of units such as mass flow and mass fraction or molar flow and mole fraction. Such series of equations are often called Kremser equations and are convenient to use. If A varies slightly from the inlet to the outlet, the geometric average of the two values can be used, with the value of m at the dilute end being used for both values of A. 

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