Solution absorbing

K2CO2 and K salt solutions absorb SO2 forming K SO which is converted to thiosulfate, KHSO which is converted to H2S, and regenerates K CO. ... [Pg.390]

It is often experimentally convenient to use an analytical method that provides an instrumental signal that is proportional to concentration, rather than providing an absolute concentration, and such methods readily yield the ratio clc°. Solution absorbance, fluorescence intensity, and conductance are examples of this type of instrument response. The requirements are that the reactants and products both give a signal that is directly proportional to their concentrations and that there be an experimentally usable change in the observed property as the reactants are transformed into the products. We take absorption spectroscopy as an example, so that Beer s law is the functional relationship between absorbance and concentration. Let A be the reactant and Z the product. We then require that Ea ez, where e signifies a molar absorptivity. As initial conditions (t = 0) we set Ca = ca and cz = 0. The mass balance relationship Eq. (2-47) relates Ca and cz, where c is the product concentration at infinity time, that is, when the reaction is essentially complete. [Pg.34]

We have next to consider the measurement of the relaxation times. Each t is the reciprocal of an apparent first-order rate constant, so the problem is identical with problems considered in Chapters 2 and 3. If the system possesses a single relaxation time, a semilogarithmic first-order plot suffices to estimate t. The analytical response is often solution absorbance, or an electrical signal proportional to absorbance or to another physical property. As shown in Section 2.3 (Treatment of Instrument Response Data), the appropriate plotting function is In (A, - Aa=), where A, is the... [Pg.142]

We have been studying the novel process for CO2 separation named membrane/absorption hybrid method. The advantages of this process are that high gas permeance and selectivity were obtained. The concept of this process is shown in Fig. 1. Both feed gas and absorbent solution are supplied to the inside of hollow fibers. While Ae liquid flows upward inside the hollow fibers, absorbent solution absorbs CO2 selectively and it becomes a rich solution. Most of rich solution permeates the membrane to the permeate side maintained at reduced pressure, where it liberated CO2 to become a lean solution. Compared to a conventional gas absorption... [Pg.409]

Ito and Matsuda studied the y-radiolysis of 2-methyltetrahydrofuran (MTHF) solutions of diphenyl sulfone and dibenzothiophene-S,S-dioxide (DBTSD) at 77 K. They found that the radical anions of these sulfone compounds are formed and have intense absorption bands at 1030 nm and 850 nm, respectively. The blue glassy solution of y-irradiated diphenyl sulfone has absorption bands at both 1030 nm and 360 nm while the absorption spectrum of the benzenesulfonyl radical formed by UV irradiation of diphenyl sulfone solution at 77 K showed only a peak at 382 nm. Gamma-irradiated phenyl methyl sulfone solution showed an absorption band only at 385 nm. Consequently the appearance of the absorption bands in 800-1030 nm of diphenyl sulfone and DBTSD may suggest that the unpaired electron is delocalized on two phenyl rings. The same authors studied the radiolysis of MTHF solutions of disulfones (diphenyl and dihexyl disulfones). They found a blue coloring of the solution by the y-radiolysis of diphenyl disulfone and dihexyl disulfone due to absorption peaks at 695 nm and 690 nm respectively, besides smaller absorptions at 300-400 nm. Comparing these results to the previous observation, that phenyl methyl sulfone solution absorbs only at 398 nm, results in the conclusion that the absorption band at 690 nm is due to the linked two sulfone moieties. The authors found that substituents on the phenyl ring lead to shifts in the absorption maxima of the... [Pg.912]

The most accurate solution actinometer currently available is the potassium ferrioxalate actinometer. Potassium ferrioxalate solutions absorb light in the range 250-509 nm. This broad range is both an advantage and a disadvantage since the solutions are sensitive to room light and must be carefully shielded from light until the intensity determination is made ... [Pg.34]

Here M, is the mass of solute absorbed or desorbed at time t and Mm is the total mass of solute absorbed or desorbed at equilibrium. This equation is accurate to within 1% for MJM < 0.6. [Pg.539]

A poorly stoppered dropping bottle of silver nitrate solution absorbed sufficient acetylene from the atmosphere in an acetylene plant laboratory to block the dropping tube. A violent detonation occurred on moving the dropping tube. [Pg.250]

Figure lb reports the UV-Visible spectrum of the liquid 1,4-bis(triethoxysilyl)benzene, the precursor of the phenylene-bridged PMO, into which traces of iodine have been dissolved. Only one band due to iodine is visible at 362 nm. We suggest this band to be due to I3" ion, which in aqueous solution absorbs at 355 nm [8], The presence of a band at the same wavelength in the case of I2 adsorbed onto AW-Ph-HMM reveals, also in... [Pg.235]

When a molecule in a solution absorbs light, an electron in the highest occupied molecular orbital (HOMO) is excited to the lowest unoccupied molecular orbital (LUMO) creating an electron vacancy, that is, a hole in the HOMO. The electron may be provided to a molecule in the solution to reduce it, whereas the hole in the HOMO may be provided to a molecule in the solution to oxidize it. This is similar to the reduction-oxidation process in the bulk semiconductor/electrolyte photoelectrolytic cell described earlier [13,17]. [Pg.243]

Diastase number was measured using a buffered solution of starch according to AOAC [10], HMF was determined colorimetrically after dilution with distilled water and addition of p-toluidine solution. Absorbance of the solution was determined at 550 run using a spectrophotometer (HP 8450A UV/VIS). Three replicate analyzes were performed from each sample for data reliability. [Pg.236]

The mass, m, is the mass of the solution, because the solution absorbs the heat. When a dilute aqueous solution is used in a calorimeter, you can assume that the solution has the same density and specific heat capacity as pure water. As you saw above, you can also assume that the heat capacity of the calorimeter is negligible. In other words, you can assume that all the heat that is released or absorbed by the reaction is absorbed or released by the solution. [Pg.236]

The interconversion of a- and 7r-allyl complexes has been observed by Kwiatek, Mador, and Seyler in the interesting homogeneous catalytic system of potassium pentacyanocobaltate(II), K3Co(CN)5 (46). This solution absorbs molecular hydrogen to form the active hydride species, Kj[Co (CN)jH]. Addition of butadiene to the hydride results in the formation of a [Pg.36]

Another colorimetric method of the associated PEG-lipid might be performed using the method described by Baleux (51). This assay consists of the formation of a complex between the PEG moiety and iodine forming a solution absorbing at 500 nm. This method is less sensitive than the previous one because it does not rely on a specific chemical function on the PEG, although it allows for wider type of PEG-lipid to be quantified. [Pg.283]

White crystal, powder or flake highly hygroscopic the compound and its solutions absorb moisture from the air at various rates depending on calcium chloride concentrations, relative humidity and vapor pressure of water in the air, temperature, surface area of exposed material, and the rate of air circulation at 40% and 95% relative humidity and 25°C, one gram anhydrous calcium chloride may absorb about 1.4 g and 17 g water, respectively. (Shearer, W. L. 1978. In Kirk-Othmer Encyclopedia of Chemical Technology, 3rd ed., vol. 4, pp. 432-6. New York Wiley Interscience) density 2.15, 2.24, 1.85, 1.83 and 1.71 g/cm for the anhydrous salt and its mono-, di-, tetra- and hexahy-drates, respectively anhydrous salts melts at 772°C, while the mono-, di-, tetra- and hexahydrates decompose at 260°, 175°, 45.5° and 30°C, respectively the anhydrous salt vaporizes at 1,935°C highly soluble in water, moderate to high solubility in alcohol. [Pg.162]

For beading oils, the most probable pathway is mass transfer in series. Assuming a shuttle effect of the oil phase, investigators consider that the solute absorbed in the oil droplets near the gas-aqueous phase interface is given up to the water phase outside the boundary layer. [Pg.593]

Proteins in solution absorb ultraviolet light with absorbance max at 280 and 200 nm (Wang 1992). Amino acids with aromatic rings are the primary reason for the absorbance peak at 280 nm. Peptide bonds are primarily responsible for the peak at... [Pg.148]

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