bluuebunny/crossref_metadata_2025 huggingface dataset:
Photolysis of 1,1,1‐trifluoromethylazomethane as a source of methyl and trifluoromethyl radicals
Authors: Craig N. L. , Setser D. W.
Published: January 2005

The photochemistry of 1,1,1‐trifluoromethylazomethane has been partially characterized. The quantum yield for N2 formation from photolysis at 366 nm and room temperature was unity at low pressure and decreased to 0.5 at 630 torr. At room temperature the principal products were C2H6, C2F6, CH3CF3 (or CH2CF2 + HF at reduced pressures), plus substituted hydrazines, which mainly arise from addition of CF3 to the parent followed by combination of these radicals with CH3 or CF3. These fluorinated methyl hydrazine products detract from the general utility of CF3‐N2‐R compounds as sources for simultaneous study of the chemistry of CF3 and R radicals. At room temperature the hydrazine products accounted for more than 50% of the total yield; however, these products can be reduced by lowering the temperature and at 195°K their yields are negligible. The quantum yield for intramolecular (direct) formation of CH3CF3 + N2 was shown to be ≤0.002.
The correction of rate data for the effects of internal temperature change
Authors: Boddington T. , Gray P. , Tyler B. J.
Published: January 2005

The effect of reactant self‐heating or cooling upon rate data is considered, and three approaches to the problem of obtaining valid kinetic parameters are described in detail. A comparison of these approaches emphasises the need to assess and allow for thermal effects during the initial planning of kinetic experiments if satisfactory results are to be acquired. An integrated rate expression is given for use with nonisothermal data, and is used to provide correction factors for rate constants which have been derived without allowance for thermal effects.
The reaction of O(3P) with C2HCl3
Authors: Sanhueza Eugenio , Heicklen Julian
Published: January 2005

The reaction of O(3P), prepared from the Hg photosensitization of N2O, with C2HCl3 was studied at 25°C. The products of the reaction in the absence of O2 were CO, CHCl3, and polymer (as well as N2 from the N2O). The quantum yields of CO and CHCl3 were 0.23 ± 0.01 and 0.14 ± 0.05, is respectively independent of reaction conditions. The reaction mechanism is

equation image

with k14a/k14 = 0.23, where k14a + k14b. Most of the HCl and CCl2 combine to form CHCl3, but some other products must also be formed to account for the difference in the CO and CHCl3 quantum yields. The C2HCl3O* adduct polymerizes without involving additional C2HCl3 molecules, since the quantum yield of C2HCl3 disappearance, Φ{C2HCl3}, was about 1.0 at high values of [N2O]/[C2HCl3]. The rate coefficient for the reaction of O(3P) with C2HCl3 is 0.10 that for the reaction of O(3P) with C2F4.

In the presence of O2 the free radical chain oxidation occurs because of the reaction

equation image

The main product is CHCl2CCl(O) with smaller amounts of CO and CCl2O, and some CO2. The chain lengths were long and values of  Φ {C2HCl3} up to 90 were observed.
Vibrational relaxation of HF(v = 1) by F atoms
Authors: Thommarson Ronald L. , Berend George C.
Published: January 2005

The rate of vibrational relaxation of HF(v = 1) by F atoms has been calculated using quasi‐classical trajectory techniques. An attempt has been made to account for the effects of multiple potential energy surfaces on the vibrational relaxation efficiency within the electronically adiabatic assumption. Toward this end two potential energy surfaces were investigated. The LEPS equation was used to construct a reactive surface for F + HF′ → FH + F′ having a reaction barrier height of 5.4 kcal/mole, which is in agreement with a bond energy‐bond order prediction. A nonreactive interaction potential consisting of atom‐atom Morse functions was calibrated to Noble and Kortzeborn's [J. Chem. Phys. 52, 5375 (1970)] LCAO‐MO‐SCF results for FHF(2II). The results are in qualitative agreement with experiment. However, the nonreactive surface appears to be too repulsive, and consequently, the contribution of collisions on the nonreactive surface to the total vibrational relaxation rate coefficient are overestimated.
Very low‐pressure pyrolysis (VLPP) of t‐butylmethyl ether
Authors: Choo Kwang Yul , Golden David M. , Benson Sidney W.
Published: January 2005

The thermal decomposition of t‐butylmethyl ether has been studied using the VLPP technique. The recommended Arrhenius parameters for the molecular elimination, reaction (1), are A(800°K) = 101 3, 9 sec−1 and Ea (800°K) = 59.0 ± 1.0 kcal/mole. No radical reactions occur under the conditions used.
magnified image
These parameters are in good agreement with earlier experimental work and with theoretical estimates of both A and E.
Kinetics of the reversible reaction between arsenious acid and aqueous iodine
Authors: Pendlebury J. N. , Smith R. H.
Published: January 2005

The kinetics of the reversible reaction

have been studied spectrophotometrically in acid solution under conditions in which both the forward and reverse reactions go to virtual completionand in which the reaction comes to a practical equlibrium. The rates of theforward (Rf) and reverse (Rr) reactions are given by

where f, g, h, u, and v have the values (4 ± 1) × 10−5 mole/1.·s, (4.2 ± 0.2) × 10−5 mole2/1.2·s, (5.0 · 0.3) × 10−7 mole3/1.3·s, (1.1 ± 0.1) × 10−3 1.2/mole2·s, and (3.7 ± 0.2) × 10−3 1.3/mole3·s at 298.2°K and at an ionic strength of 2.00M maintained by adding sodium chloride. The stoichiometric equilibrium constant under similar conditions is 0.022 ± 0.003. Differentvalues of these parameters were obtained when sodium perchlorate and sodiumnitrate were used to control ionic strength.

The results are compared with those from previous reports and a mechanism is proposed based upon an initial rapid equilibrium

followed by a rate‐determining attack of water upon H3AsO3I+, H2AsO3I, and HAsO3I−.
The kinetics of the decarboxylation of malonic acid in normal alkanols
Authors: Clark Louis Watts
Published: January 2005

Rate constants and activation parameters are reported for the decarboxylation of malonic acid in seven normal alkanols (butanol‐l to decanol‐l inclusive). It is found that the enthalpy of activation of the reaction is a linear function of the number of carbon atoms in the hydrocarbon chain of tthe solvent, expressed by the equation: ΔH≠ = –600n + 30,000, where n is thenumber of carbon atoms in the chain. Also an equation is developed relatingthe rate constant for the decarboxylation of malonic acid in normal alkanols to n (the number of carbon atoms in the chain): log K = 10.854283 – 0.3212674n + (131.136876n – 6556.5438)/T + log T. With the aid of this equation rate constants may be calulated for the decarboxylationof malonic acid in any alcohol at any temperature which agree with experimental values to within the limit of error of the experiments. A comparison of the data obtained in the present research for the decarboxylation of malonic acid in normal alkanols with previously reported data for the reaction in amines indicates that for reaction taking place in alcohols the transition state probably contains two molecules of solvent but only one for the reaction in amines.
Determination by the phase shift method of the absolute rate constants of reactions of O(3P) atoms with olefins at 25°C
Authors: Furuyama Shozo , Atkinson Roger , Colussi Agustin J. , Cvetanović R. J.
Published: January 2005

Technical improvements have been made in the application of the phase shift method, recently developed and used in this laboratory to measure the absolute values of the rate constants of the reactions of O(3P) atoms with ethylene, propylene, 1‐butene, and isobutene. More accurate rate constants have now been obtained for these olefins and themeasurements have been also extended to three additional olefins (cis‐2‐butene, trimethylethylene, and tetramethylene).The mean least squares values of the rate constants of the reactions of O(3P) with olefins at 26°C, expressed as k2 × 10−9 (1./mole2·sec), and their standard deviations are ethylene 0.43 ±0.05, propelene 2.02 ± 0.17, 1‐butene 2.40 ± 0.32, isobutene 9.85 ± 1.34, cis‐2‐butene 9.00 ± 1.76, trimethylethylene 31.1 ± 3.0, and tetramethylethylene 44.4 ± 4.1. A Value of (5.78 ± 0.08) × 1010l.2/mole2·sec was obtained for the rate constant of the reaction O(3P) + NO + M, with M = N2O. Where comparison with the absolute rate constants in the literature is possible, agreement is very good, especiallywith some recent absolute values obtained by entirely different experimental techniques. Consistency with the relative rate constant of the O(3P) reactions with olefins previously determined in this laboratory, is excellent.
Vibration–Vibration energy exchange between N2O and CO
Authors: Suitor Jerry W. , Kuby W. C.
Published: January 2005

The temperature dependence of the vibration–vibration energy transfer between the v3 mode of N2O and the first vibrational level of CO was determined over a range of 780 to 1400°K using a shock tube. Several mixtures of CO‐N2O were tested, diluted in 95% Ar. The Landau–Teller plot of the vibration–vibration relaxation times has a least squares line of

where pτvv is in atm ˙μsec and T in °K. The measured kinetic reaction was determined to be

The transfer probabilities for this process were found to vary directly with temperature.
The rate constant of the reaction HO2 + COCO2 + OH
Authors: Vardanyan I. A. , Sachyan G. A. , Nalbandyan A. B.
Published: January 2005

The high‐temperature oxidation of formaldehyde in the presence of carbon monoxide was investigated to determine the rate constant of the reaction HO2 + CO  CO2 + OH (10). In the temperature range of 878–952°K from the initial parts of the kinetic curves of the HO2 radicals and CO2 accumulation at small extents of the reaction, when the quantity of the reacted formaldehyde does not exceed 10%, it was determined that the rate constant k10 is

A computer program was used to solve the system of differential equations which correspond to the high‐temperature oxidation of formaldehyde in the presence of carbon monoxide. The computation confirmed the experimental results. Also discussed are existing experimental data related to the reaction of HO2 with CO.
Hydrogen abstraction by fluorine atoms under conditions of thermal initiation: Hydrocarbons and fluorinated hydrocarbons
Authors: Manning Ronald G. , Grant Edward R. , Merrill Jerald C. , Parks Norris J. , Root John W.
Published: January 2005

Modified nuclear recoil techniques have been used to obtain accurate relative bimolecular rate coefficients for thermally induced hydrogen abstraction reactions by atomic fluorine. New results are reported for 12 hydrocarbons and partially fluorinated hydrocarbons studied at 303°K.
The mechanism of the isomerization of cis‐2‐butene photosensitized by sulfur dioxide excited within the first allowed band at 3130Å
Authors: Demerjian Kenneth L. , Calvert Jack G.
Published: January 2005

The mechanism of the electronically excited sulfur‐dioxide sensitized isomerization of cis‐2‐butene has been studied through the measurement of the initial quantum yields of trans‐2‐butene formation in 3130‐A irradiated gaseous binary mixtures of SO2 and cis‐2‐butene and ternary mixtures of SO2, cis‐2‐butene, and CO2. The kinetic treatment of the present data from the SO2C4H8 mixtures and those of recent similar studies of Penzhorn and Güsten [3] and Cox [4] are all consistent with the involvement of only the long‐lived fluorescent 1B1 and phosphorescent 3B1 states of SO2 in the isomerization mechanism. The data give (k2a + k2b)=0.21±0.04; SO2(1B1) + SO2 → SO2(3B1) + SO2(2a); SO2(1B1) + SO2 → (2SO2) (2b). The analogous intersystem crossing ratio for the SO2(1B1)‐cis‐2‐butene quenching collisions is the largest observed among the many quencher molecules studied; the value lies in the range of 0.85 to 0.37, with the extremes representing different choices of alternative data and possible mechanisms. From the present data the ratio of the SO2(3B1) quenching rate constant with SO2 to that with cis‐2‐butene as quencher is estimated to be (2.7±1.2) × 10−3, in good agreement with our directly measured ratio from lifetime studies (2.91±0.23) × 10−3 [30−32], and the value found in isomerization studies by Cox (2.40±0.09) × 10−3 [4]. The simple two‐excited state mechanism, which is seemingly applicable to the relatively low‐pressure binary SO2‐butene mixture results, is not adequate to explain the data obtained in experiments with large quantities of added CO2 gas. Here an “excess” quantum yield of isomerization is observed. Several alternative mechanisms can be used to rationalize these results, but all alternatives must incorporate some other excited SO2 species (X) as well as SO2(3B1) and SO2(1B1). The kinetics suggest that the ill‐defined state is unreactive toward the olefin and decays nonradiatively to SO2 largely in experiments at the lower pressures, X → SO2 (11); it may generate SO2(3B1) in a collisionally induced process at high added inert gas (CO2) pressures, X + CO2 → SO2(3B1) + CO2 (10a) and X + CO2 → SO2 + CO2 (10b). The data give k11/(k10a + k10b)=0.026 mole/l.
The kinetics of the reaction of O(3P) and D atoms with cyclohexane
Authors: Kim Poongzag , Timmons Richard B.
Published: January 2005

The kinetics of the reactions of O(3P) and D atoms with cyclohexane have been investigated using fast‐flow techniques. The rates of reaction were computed by monitoring changes in both atom and cyclohexane concentrations using electron spin resonance and mass spectrometric methods, respectively. The O(3P) + C6H12 reaction was studied over a temperature range of 344 to 513°K and we obtain a specific rate constant of (3.2±0.6) × 1014 exp (−4400±400/RT) cm3/mole˙sec for this reaction. The only reaction product detectable mass spectrometrically under flow conditions of excess oxygen atoms is formaldehyde.

The D + C6H12 reaction was studied over a temperature range of 297 to 596°K. A specific rate constant of (4.1±1.0) × 1013 exp (−4000±300/RT) cm3/mole˙sec was obtained for this reaction. On the basis of the results obtained in these studies, the important primary process in both the O(3P) and D atom reactions is concluded to be abstraction of a hydrogen atom from the cyclohexane molecule.
The photochemistry of sulfur dioxide excited within its first allowed band (3130 Å) and the “forbidden” band (3700–;4000 Å)
Authors: Chung Kuenja , Calvert Jack G. , Bottenheim Jan W.
Published: January 2005

The quantum yields of SO3 formation have been determined in pure SO2 and in SO2 mixtures with NO, CO2, and O2 using both flow and static systems. In separate series of experiments excitation of SO2 was effected within the forbidden band, SO2(3B1) ← \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm SO}_2 (\tilde X,^1 A_1 ) $$\end{document}, and within the first allowed singlet band at 3130 Å. The values of Φ were found to be sensitive to the flow rate of the reactants. These results and the apparently divergent quantum yield results of Cox [10], Allen and coworkers [24, 26, 29], and Okuda and coworkers [11] were rationalized quantitatively in terms of the significant occurrence of the reactions SO + SO3 → 2SO2 (2), and 2SO → SO2 + S [or (SO)2] (3), in experiments of long residence time. From the present rate data, values of the rate constants were estimated, k2=(1.2±0.7) × 106; k3=(5±4) × 105 l˙/mole · sec. Φ values from triplet excitation experiments at high flow rates of NOSO2 and CO2SO2 mixtures showed the sole reactant with SO2 leading to SO3 formation in this system to be SO2(3B1); SO2(3B1) + SO2 → SO3 + SO(3Σ−) (la); k=(4.2±0.4) × 107 l./mole · sec. With excitation of SO2 at 3130 Å both singlet and triplet excited states play a role in SO3 formation. If the reactive singlet state is 1B1, the long‐lived fluorescent state, SO2(1B1) + SO2 → SO3 + SO (1 Δ or 3Σ−) (lb), then k=(2.2±0.5) × 109 l./mole · sec. From the observed inhibition of SO formation by added nitric oxide, it was found that the SO3‐forming triplet state, generated in this singlet excited SO2 system, had a relative reactivity toward SO2 and NO which was equal within the experimental error to that observed here for the SO2(3B1) species. Either SO2(3B1) molecules were created with an unexpectedly high efficiency in 3130 Å excited SO2(1B1) quenching collisions, or another reactive triplet (presumably 3A2 or 3B2) of almost identical reactivity to SO2(3B1) was important here.
High‐temperature pyrolysis of acetaldehyde
Authors: Colket M. B. , Naegeli D. W. , Glassman I.
Published: January 2005

High‐temperature (>1000°K) pyrolysis of acetaldehyde (∼1% in an atmosphere of pure nitrogen) was examined in a turbulent flow reactor which permits accurate determination of the spatial distribution of the stable species. Results show that the products in order of decreasing importance are CO, CH4, H2, C2H6, and C2H4. Rates of formation were consistent with the Rice–Herzfeld mechanism by including reactions to explain C2H4 formation and the possible presence of ketene. A steady‐state treatment of the complete mechanism indicates that the overall reaction order decreases from \documentclass{article}\pagestyle{empty}\begin{document}$ \frac{3}{2} $\end{document} to 1, which is supported by the new experimental data. Using earlier low‐temperature results, the rate constant for the reaction CH3CHO → CH3 + CHO (1) was found as k1=1015.85±0.21 exp (−81,775±1000/RT) sec−1. Also, data for the ratio of rate constants for reactions CH3CHO + CH3 → CH4 + CH3CO (4) and 2CH3 → C2H6(6) were fitted to the empirical expression k4/k61/2=10−13.89±0.03T6.1 exp(−1720±70/RT) (cm3/mole·sec)1/2 and causes for the curvature are discussed. The noncatalytic effect of oxygen on acetaldehyde pyrolysis at high temperature is explained.
Competitive study of the reactions Br + RFI → IBr + RF and determination of bond dissociation energies D(RF−I) where RF = CF3, C2F5, n‐;C3F7, i‐C3F7, and n‐C4F9
Authors: Okafo Ernest N. , Whittle Eric
Published: January 2005

The overall photobromination reactions

have been studied using a competitive technique. Relative Arrhenius parameters were obtained for the rate‐determining step
equation image

These were placed on an absolute basis using previous‐absolute values of A and E for RFI=CF3I. The activation energies were used to calculate bond dissociation energies D(RI) with the following results:

RF−
E16
D(RF−I)(kcal/mole)

CF3I
10.8
52.6

C2F5I
8.8
50.6

n‐C3F7I
7.4
49.2

i‐C3F7I
7.5
49.2

n‐C4F9I
6.7
48.4

E16 from [1]

The D(RI) are compared with related D(RI) and it is concluded that for a given alkyl group RH and the corresponding perfuloroalkyl group RF, D(RI) > D(RI) whereas it has previously been found that D(RX;) < D(RX) where X is not iodine.
The oxidation of CFClCFCl and CF2CCl2
Authors: Sanhueza Eugenio , Heicklen Julian
Published: January 2005

The oxidation of CFClCFCl and CF2CCl2 were studied at room temperature by chlorine‐ and oxygen‐atom initiation. The chlorine‐atom initiated oxidation of CFClCFCl yields CCl2FCF(O) as the exclusive product. Its quantum yield is ∼420, which gives k3a/k3b=210 where reactions (3a) and (3b) are
equation image
The O(3P)CFClCFCl reaction gives CClFO with a quantum yield of 0.80, polymer, and small amounts of an unidentified product which is probably cyclo‐(CFCl)3. Thereaction paths are
equation image
with k9a/k9=0.80. The overall reaction of O(3P) with CFClCFCl proceed one fifth as fast as the O(3P)‐C2F4 reaction. When O2 is also present, the same free‐radical chain oxidation occurs by O(3P)initiation as by chlorine‐atom initiation.

The chlorine‐atom initiated oxidation of CF2CCl2 gives CF2ClCCl(O) as the major product, with quantum yields ranging from 42 to 85. Smaller amounts of CF2O and CCl2O are produced in equal amounts with quantum yields of ∼3.5. The reactions responsible for the products are
equation image
The O(3P)‐CF2CCl2interaction yields CF2O and
equation image
with quantum yields of 1.0 and ∼0.85, respectively. In thepresence of O2 the radical chain products are observed, but the mechanism is different than that for other chloroolefins.
The kinetics of the deparotonation of tropaeolin O
Authors: Perlmutter‐Hayman Berta , Shinar Ruth
Published: January 2005

The reaction between tropaeolin O and hydroxyl ions has been reinvestigated in the pH range between 10.8 and 12.2 at 25°C and an ionic strength I of 0.1 M, using the T‐jump method. The rate constants obtained from results at pH ≥ 11.66 are in satisfactory agreement with previous data. At lower pH, however, the rate is found to increase with decreasing hydroxyl‐ion concentration. A mechanism which is compatible with these results is proposed and discussed. The dissociation constant of the last proton at I=0.1 M has been redetermined and found to be in satisfactory agreement with values given in the literature.
Shift of the rate‐determining step in a consecutive chemical reaction with variation of the reaction affinity
Authors: Enyo M.
Published: January 2005

A consecutive single‐route reaction is considered. When two (groups of) steps compete in controlling the overall reaction rate, there exists a general rule that the earlier step in the flow of the overall reaction tends to be rate‐determining with the increase of the reaction affinity. The latter may, however, be distributed more or less evenly to both steps.
Pyrolysis of [5‐14C]‐1‐pentene–evidence for homoallylic rearrangements at 873 K
Authors: Kopinke F.‐D. , Zimmermann G. , Bach G. , Ondruschka B.
Published: January 2005

It was found that the pyrolysis of [5‐14C]‐1‐pentene gives radioactive 1,3‐butadiene. This result can be explained in terms of a sequence of free radical rearrangements of 1‐penten‐3‐yl radicals. From this and additional information on isotope distribution in butadiene formed from different deuterated 1‐pentenes, we conclude that homoallylic rearrangement of 1‐penten‐4‐yl and 2‐penten‐5‐yl radicals is the dominant route for their consumption.
Kinetics of the solvolysis of the trans‐chloroazidobis(diaminoethane)cobalt (III) ion in water + t‐Butyl Alcohol Mixtures
Authors: Eid Ali E. , Wells Cecil F.
Published: January 2005

The kinetics of the solvolysis of the ion trans‐[Coen2N3Cl]+ have been investigated at several temperatures in mixtures of water with t‐butyl alcohol with concentrations of the latter ranging up to 50 vol% or a mol fraction of 0.16. Values for the enthalpy and entropy of activation show sharp changes with changing solvent composition which can be correlated with extrema in the physical properties of the mixture concerned with sharp changes in solvent structure. Plots of log(rate constant) against the reciprocal of the dielectric constant and against the Grunwald‐Winstein Y factor are both curved. The application of a free energy cycle shows that the effect of changes in solvent structure on the solvolysis dominates on the cobalt(III) cation in the transition state over that on the cation in the initial state.
Gas‐phase thermolysis of sulfur compounds. Part VIII. Chloromethyl allyl, cyanomethyl allyl, 1‐cyanoethyl allyl and neopentyl allyl sulfides
Authors: Martin Gonzalo , Martinez Henry , Suhr Harald , Suhr Ursula
Published: January 2005

The pyrolyses of four alkyl allyl sulfides with substituents on the αC atom of the alkyl moiety have been studied in a stirred‐flow system over the temperature range 340‐400°C and pressures between 2 and 12 torr. The only products formed are propene and thioaldehydes. The reactions showed first‐order kinetics with the rate coefficients following the Arrhenius equations: Chloromethyl allyl sulfide:

Cyanomethyl allyl sulfide:

1‐cyanoethyl allyl sulfide:

Neopentyl allyl sulfide:

The effects of these and other substituents on the reactivity is discussed in relation with the stabilization of a polar six‐centered transition state. The results support a non‐concerted mechanism where the 1–5 αH atom shift is assisted by its acidic character.
The high temperature pyrolysis of ethylbenzene: Evidence for dissociation to benzyl and methyl radicals
Authors: Mizerka L. J. , Kiefer J. H.
Published: January 2005

The pyrolysis of ethylbenzene has been investigated in shock waves with the laser schlieren technique. Mixtures of 1 and 2% ethylbenzene in krypton were studied for reaction conditions of 1300‐1800 K, 70‐550 torr. At high temperatures, the initial rapid endothermic dissociation is followed by a region of net exothermic reaction, which is readily understood as arising mainly from methyl radical recombination after dissociation to methyl and benzyl radicals. The initial unimolecular dissociation rates show no detectable dependence on pressure; with ΔH0298 = 75.7 kcal mol−1 these rates are

An RRKM extrapolation suggests

in excellent agreement with previous lower temperature data.
Kinetics of the solvolysis of the trans‐dichlorobis(1,2‐diaminoethane)‐cobalt(III) Ion in water + urea mixtures
Authors: Groves Grahame S. , Wells Cecil F.
Published: January 2005

Following the kinetic investigation of the solvolysis of a range of cobalt(III) complexes in mixtures of water + cosolvent wherethe cosolvent enhances the solvent structure and decreases the dielectric constant, kinetic data are now reported for such a solvolysis in water + urea where urea acts as a structure breaker and enhances the dielectric constant. A plot of log (rate constant) against reciprocal of the dielectric constant shows that differential effects of changes in solvent structure occur between the initial and the transition states and, as in theinvestigations using structure‐enhancing cosolvents, the principal effect of change in solvent structure on the cobalt(III) cation occurs on the penta‐coordinated ion in the transition state.
Rate constants for the reactions of isobutyl, neopentyl, cyclopentyl, and cyclohexyl radicals with molecular oxygen
Authors: Wu Dihua , Bayes Kyle D.
Published: January 2005

Rate constants have been measured for the reactions of four hydrocarbon radicals with O2 in the gas phase at room temperature. Laserflash photolysis was used to generate low concentrations of radicals. A photoinization mass spectrometer followed the radical loss as a function of time. The measured pseudo first‐order decay rate of the radical and the absolute oxygen concentration were combined to give the absolute rate constants (in units of 10−12 cm3 molec−1 s−1): isobutyl (2.9 ± 0.7); neopentyl (1.6 ± 0.3); cyclopentyl (17 ± 3); and cyclohexyl (14 ± 2). The cycloalkyl radicals have rate constants similar to those of other secondary radicals. However, the isobutyl and neopentyl radicals react more slowly than similar primary radicals. These new rate constants are compared in Figure 2 with the recently published correlation of reactive cross section with radical ionization potential.
Kinetics of the reactions of naphthalene, 2‐methylnaphthalene, and 2,3‐dimethylnaphthalene with OH radicals and with O3 at 295 ± 1 K
Authors: Atkinson Roger , Aschmann Sara M.
Published: January 2005

The kinetics of the gas‐phase reactions of naphthalene, 2‐methylnaphthalene, and 2,3‐dimethylnaphthalene with O3 and with OH radicals have been studied at 295 ± 1 K in one atmosphere of air. Upper limit rate constants for the O3 reactions of <3 × 10−19, <4 × 10−19, and <4 × 10−19 cm3 molecule−1 s−1 were obtained for naphthalene, 2‐methylnaphthalene, and 2,3‐dimethylnaphthalene, respectively. For the OH radical reactions, rate constants of (in units of 10−11 cm3 molecule−1 s−1) 2.59 ± 0.24, 5.23 ± 0.42, and 7.68 ± 0.48 were determined for naphthalene, 2±methylnaphthalene, and 2,3‐dimethylnaphthalene, respectively. These data show that under atmospheric conditions these naphthalenes will react mainly with the OH radical, with life‐times due to this reaction ranging from ca. 11 h for naphthalene to ca. 4 h for 2,3‐dimethylnaphthalene.
Kinetic analysis of the disproportionation of aqueous glyoxal
Authors: Fratzke Alfred R. , Reilly Peter J.
Published: January 2005

Rates of disproportionation of 0.015–0.4 mM aqueous glyoxal toglycolic acid were measured at 0.24–75 mM NaOH and constant ionic strength, leading to the empirical rate expression r = (a1[OH−] + a2[OH−]2) [GT]/(1 + a3[OH−]), where [GT] is the total glyoxal concentration. These results were confirmed in bicarbonate/carbonate buffer and at 2–20 mM [GT]. The rate form is in contradiction to earlier work on glyoxal, which suggested a second‐order dependence on [OH−], but agrees with the rate equation for phenylglyoxal disproportionation. The kinetic data can be explained by a mechanism postulating the presence of monohydrated and dihydrated forms of glyoxal in equilibrium, with the rate‐limiting steps being intramolecular hydride ion transfers to the unhydrated carbonyl carbon of the mono‐ and divalent anions of glyoxal monohydrate.
Thermodynamic and kinetic analysis of the dimerization of aqueous glyoxal
Authors: Fratzke Alfred R. , Reilly Peter J.
Published: January 2005

Equilibria and rates of interconversion between monomeric and dimeric glyoxal were measured in aqueous solution. The equilibrium constant [G2]/[G1]2 was 0.56 M−1 at 25°C, and was hardly affected by changes of ionic strength and pH but increased rapidly with increase of temperature. The rate of depolymerization was first‐order in dimer, with the pseudo first‐order rate coefficient in the pH range 1.3–7.8being of the form b1[H3O+] + b2 + b3[OH−]/(1 + b4[OH−]) + b5[OH−]. Coefficients b1 and b2 were more strongly affected by changes of temperature, though [OH−] was much the more effective catalyst. This rate form has not previously been observed for monomer‐dimer inter‐conversion of α‐hydroxycarbonyls and α‐dicarbonyls or for related reactions such as mutarotations and hydrations. Equivalent rate forms arisefrom reactions where an intermediate at steady state and low concentration is produced.
Unified approach for Euler–Lagrange equation arising in calculus of variations
Authors: Naidu D. S. , Imura Y.
Published: January 2005

We address the development of a unified approach for the necessary conditions for optimization of a functional arising in calculus of variations. In particular, we develop a unified approach for the Euler–Lagrange equation, that is simultaneously applicable to both shift (q)‐operator‐based discrete‐time systems and the derivative (d/dt)‐operator‐based continuous‐time systems. It is shown that the Euler–Lagrange results that are now obtained separately for continuous‐ and discrete‐time systems can be easily obtained from the unified approach. An illustrative example is given. Copyright © 2005 John Wiley & Sons, Ltd.
Surface modification of sisal fibers: Effects on the mechanical and thermal properties of their epoxy composites
Authors: Gañan Piedad , Garbizu Saioa , Llano‐Ponte Rodrigo , Mondragon Iñaki
Published: January 2005

The aim of this paper is to evaluate the mechanical and thermal properties of sisal fiber reinforced epoxy matrix composites as a function of modification of sisal fiber by using mercerization and silane treatments. The changes introduced by the treatments on the chemical structure of sisal fibers have been analyzed by infrared spectroscopy (FTIR). Thermal behavior of both sisal fibers and composites has been studied by thermogravimetric analysis (TGA). Both treatments clearly enhanced thermal performance and also mechanical properties of fibers, being other physical properties also modified. Mercerization, above all when combined with silanization, led to significant enhancement on mechanical properties of composites as a consequence of increasing mechanical properties of fibers and improving fiber/matrix adhesion. POLYM. COMPOS., 26:121–127, 2005. © 2005 Society of Plastics Engineers
Zur Kenntnis der komplexen anorganischen Säuren. III. Abhandlung
Authors: Kehrmann F.
Published: January 2005

Man kann die in der vorstehend gegebenen Übersicht niedergelegten bisherigen Ergebnisse meiner Untersuchung der komplexen Phosphorwolframsäuren folgendermassen aussprechen:

Beim Zusammenbringen wolframsaurer Salze mit Phosphorsäure oder Phosphaten unter verschiedenen Versuchsbedingungen findet die Bildung einer ganzen Anzahl aus Wolframsäure, Phosphorsäure und Basis bestehender, verwickelt zusammengesetzter, meist wasserhaltiger Salze statt, deren zugehörige Säure sich in vielen Fällen in freiem Zustande erhalten läst, während andere Salze nur als solche beständig sind.
Über die Dichte und Ausdehnung des weißen und grauen Roheisens im flüssigen und festen Zustande. (Dichtemessungen bei hohen Temperaturen. VIII.)
Authors: Sauerwald F. , Widawski E.
Published: January 2005

Das weiße Roheisen weist bei hohen Temperaturen im festen Zustande durchaus normale, im Sinne bekannter Gefügeänderungen verlaufende Volumengestaltung auf, ebenso beim Übergang in den flüssigen Zustand; die früher bei grauem Gußeisen bei langsamer Erwärmung zwischen 900 und 1000° festgestellte Kontraktion wurde dilatometrisch bestätigt, dabei war es möglich, als dieser Kontraktion voraufgehend und von ihr getrennt die der Perlitauflösung zugehörige dilatometrisch zu ermitteln. Das bis auf etwa l% gleiche spezifische Volumen des geschmolzenen weißen und grauen Eisens und ein sehr nahe gleicher Ausdehnungskoeffizient wurde erneut festgestellt. Die Bedingtheit der Kontraktion des festen grauen Eisens durch Graphitauflösung wurde somit sichergestellt, ebenso die früheren Schlüsse über die Bildung von Zementit beim Schmelzen des grauen Eisens. Eine Änderung des Volumens flüssigen Eisens bei konstanter Temperatur konnte wiederum nicht gefunden werden.
Über Adsorption. Nr. 9. Über die Adsorption von Gasen durch Holzkohle im Gebiete niedriger Drucke
Authors: Magnus A. , Cahn L.
Published: January 2005

1. Die Adsorption von Ammoniak und Kohlendioxyd wurde an Holzkohle bei verschiedenen Temperaturen und wechselndem Entgasungsgrad der Kohle bis zu Drucken unterhalb 0,001 mm untersucht.
Etwas über Phasengleichgewichte bei Sulfaten. II
Authors: Jänecke Ernst
Published: January 2005

Die Bedenken gegen die Darstellung des Systems PbS0 nach Herrn Schenck wurden aufrecht erhalten. Es wurde darauf hingewiesen, daß von Herrn Schenck außer Biei auch Sauerstoff im Dampf vernachlässigt worden ist.
Adsorption von Säuren, Basen und Salzen durch frischgefällte Kieselsäure
Authors: Mehrotra M. R. , Dhar N. R.
Published: January 2005

Es sind Adsorptionsversuche ausgeführt worden mit frischgefällter und gut ausgewaschener Kieselsäure und Essig‐, Propion‐. Butter‐, Citronen‐, Benzoe‐, Salicyl‐, Hippur‐, Schwefel‐, Salpeter‐ und Chlorwasserstoffsäure. Die prozentische Menge der Adsorption bei diesen Säuren geht nicht über 2,7 hinaus.
Fluorescenz, Phosphorescenz, Chemiluminescenz und Aktivierung von Molekeln
Authors: Dhar N. R.
Published: January 2005

Bei der Erscheinung der Phosphorescenz ist die Lebensdauer der aktivierten Molekeln verlängert. Der Hauptunterschied zwischen Phosphorescenz und Fluorescenz liegt in der Verlängerung der Lebensdauer der aktivierten Molekeln bei der ersten Erscheinung. Beispiele, bei denen eine Verlängerung der Lebensdauer aktivierter Molekeln stattfindet, sind angegeben worden.
Zur Photochemie der Alkali‐ und Erdalkalijodide
Authors: Stobbe Hans , Steinberger Franz Karl
Published: January 2005

Neutrale Alkalijodidlösungen sind bei Abwesenheit von Luft lichtbeständig. Dagegen erfahren sie bei der Belichtung unter kohlensäurehaltiger Luft zwei voneinander unabhängige Zersetzungen. Der erste als Hauptreaktion zu bezeichnende Vorgang beruht auf der durch die Kohlensäure hervorgerufenen Bildung von Jodwasserstoff und auf dessen Oxydation zu Wasser und Jod.
Über die innere Reibung geschmolzener Metalle und Legierungen. III. Die innere Reibung von Kupfer, Antimon, usw und Kupfer–Antimon‐, Kupfer–Zinn‐, Blei–Wismut‐Legierungen
Authors: Bienias A. , Sauerwald F.
Published: January 2005

Es wurde mitgeteilt, auf welche Weise das früher schon verwendete Resultat, daß die HAGENBACH'sche Korrektur mit dem Faktor 1 zu berechnen sei, durch direkte Beobachtung des zeitlichen Verlaufs des Durchflusses durch den Capillarapparat gewonnen wurde.
Beiträge zur Kenntnis von Hydrogelen. Über Arsenpentoxydhydrate
Authors: Simon A. , Thaler E.
Published: January 2005

1. Bei der Untersuchung der Arsenpentoxydhydrate können auf Grund von Kristallisations‐ und Abbauversuchen nur die Hydrate

erhalten werden.
Über die Verwendbarkeit der elektrometrischen Titration zur Löslichkeitsbestimmung schwerlöslicher Oxyde
Authors: Busch Werner
Published: January 2005

Die Verwendbarkeit der elektrometrischen Titration in der Alkalimetrie bzw. Acidimetrie wurde für das Gebiet stark verdünnter Lösungen nachgewiesen und die Fehlergrenzen fü die Titrationen von n/1000‐Lösungen zu 0,3 − 0,5.10−3 Grammäquivalenten ermittelt.
Über Das ternäre System Blei‐Antimon‐Arsen
Authors: Abel E. , Redlich O.
Published: January 2005

Das System PbSbAs wurde nach den Methoden der thermischen und mikrographischen Analyse untersucht. Die Eigenschaften dieses Systems entsprechen im wesentlichen dem Typus: zwei Bestandteile im festen Zustand vollkommen mischbar, Mischkristalle im dritten Bestandteil unlöslich. Die Lage der eutektischen Kristallisationen ist der Fig. 5 zu entnehmen.
Über Dreistoffsysteme mit Eisen und Kohlenstoff. I. Die Phasen „Fe3C · Cr4C’︁ und Cr10C6Fe3, die „physikalische Rückstandsanalyse”︁
Authors: Sauerwald F. , Neudecker H. , Rudolph J.
Published: January 2005

Es wurde für die Kohlenstoffbestimmung in Legierungen mit hohem Cr und C‐Gehalt fein verteiltes Kupfer als Zuschlag empfohlen.

Es wurde zur Untersuchung von Mehrstoffsystemen die Anwendung einer Untersuchungsmethode, die man ah „physikalische Rückstandsanalyse”︁ bezeichnen kann, vorgeschlagen und in einem Fall als brauchbar erwiesen.
Über einige Reaktionen und Komplexverbindungen der Rhodanwasserstoffsäure
Authors: Ormont B.
Published: January 2005

I. a) Wenn man zu einer Lösung von KCNS (bzw. NH4 CNS), von der Konzentration 1:2, tropfenweise 80–90%ige H2SO4 zu‐gibt, so wird nach 1–2 Minuten die Lösung gelb; das so erhaltene Reagens unterscheidet sich nach seinen Eigenschaften wesentlich vom neutralen KCNS.
Zur Kenntnis der Tulalegierung. (Eine Untersuchung über das Dreistoffsystem Cu2SAg2SPbS.)
Authors: Schwarz Robert , Romero Alfonso
Published: January 2005

Die vorliegende Arbeit setzt sich das Ziel, das Wesen der unter dem Namen Tula bekannten Legierung chemisch und metallographisch zu ergründen.
Zur Kenntnis von Oxydationsreaktionen. I. Über die Gewinnung von Nitraten sowie von Arsensäure
Authors: Askenasy P. , Elöd E. , Zieler Hans
Published: January 2005

Die Ergebnisse vorliegender Untersuchungen lassen sich folgendermaßen zusammenfassen:

Nitrite werden in saurer Lösung durch Sauerstoff unter Druck quantitativ in Nitrate übergeführt.

Arsenige Säure und die sulfide des Arsens werden in salpetersaurer Suspension durch Sauerstoff unter Druck quantitative in Arsensäure bzw. in diese und Schwefelsäure verwandelt. Von der dabei nur in einem Bruchteil der „stöchiometrischen Menge”︁ anzuwendenden Salpetersäure geht praktisch nichts verloren. Die gebildete Schwefelsäure läßt sich von der Arsensäure durch Zusatz von Kalk als Calciumsulfat abscheiden.

Arsenik und Arsensulfide werden in wäßriger Lösung bzw. Suspension bei Abwesenheit von Salpetersäure bei 20 at Sauerstoff und bei Temperaturen unter 200° C nur hydrolysiert, der Schwefelwasserstoff wird zu Schwefelsäure oxydiert; Arsensäure wird jedoch nicht gebildet

.
Über die Natur der magnetischen Umwandlung des Eisens
Authors: Wever Franz
Published: January 2005

Definitionen: Eine Phasenumwandlung ist thermodynamisch durch eine unstetige Änderung sämtlicher physikalischen Eigenschaften im Umwandlungspunkt gekennzeichnet; dem experimentellen Nachweis einer Phasenumwandlung steht die grundsätzliche Unmöglichkeit entgegen, Unstetigkeiten im mathematischen Sinne zu beobachten.
Änderung des Elektrischen Leitvermögens von Elektrolyten und Solen beim Altern
Authors: Dhar N. R.
Published: January 2005

Die zeitliche Zunahme des Leitvermögens von Salzlösungen wenig löslicher Säuren oder Basen ist zum Teil bedingt durch langsam verlaufende Hydrolyse. Die Geschwindigkeit der Hydrolyse hängt von der Geschwindigkeit der Keimbildung ab und von der Umwandlung der Keime in Kolloidteilchen. Die aus der wenig löslichen Säure oder Base gebildeten Kolloide verlieren im Laufe der Zeit Aktivität, Adsorptionsvermögen und Wasser, so daß die adsorbierten Elektrolyte an die Lösung abgegeben werden und hierdurch eine vermehrte Leitfähigkeit hervorrufen.
Zur Kenntnis der fundamentalen Atomgewichte. III. Revision des Atomgewichtes des Silbers. Analyse des Silbernitrats
Authors: Hönigschmid O. , Zintl E. , Thilo P.
Published: January 2005

Es wurde eine Methode zur quantitativen Analyse des Silbernitrats durch Reduktion des geschmolzenen Salzes mittels Wasserstoff ausgearbeitet. Zur Vermeidung von Versuchsfehlern, die durch Adsorption von Luft sowohl am Nitrat wie besonders an dem reduzierten Silber verursacht werden könnten, wurden die beiden Substanzen bei vier Analysen in vollkommen evakuierten Wägegläsern gewogen.
Die Anwendung von flüssigem Amalgam in der volumetrischen Analyse. IX. Einige neue Methoden zur Bestimmung von Vanadium und Wolfram
Authors: Someya Kin'Ichi
Published: January 2005

Es wurde eine neue jodometrische Methode zur Vanadiumbestimmung unter Verwendung von Zinkamalgam ausgearbeitet.

Es wurde gezeigt, daß Cuprisulfat statt Kaliumpermangat bei der oxydimetrischen, maßanalytischen Bestimmung von Wolfram benutzt werden kann.
Die Herstellung schutzkolloidfreier, gleichteiliger Silberhydrosole I
Authors: Voigt J. , Heumann J.
Published: January 2005

Im Gegensatz zu den bekannten Silberhydrosolen mit vielfarbigen Submikronen kann man auch solche mit gleichfarbigen Teilchen herstellen und damit ähnliche Verhältnisse erreichen, wie bei kolloidem Gold.
Zur Kenntnis der Cyanverbindungen der Platinmetalle
Authors: Krauss F. , Schrader G.
Published: January 2005

1. Die Doppelcyanide des Ruthenium leiten sich den älteren Angaben entsprechend von der Säure H4[Ru(CN)6], also vom zweiwertigen Ruthenium, ab.
Studien über die Überspannung. III. Die Beziehung zwischen der Wasserstoffüberspannung, der Oberflächenspannung und der Konzentration der Lösung
Authors: Onoda Tadashi
Published: January 2005

1. Unter Verwendung von Schwefel oder Chlorwasserstoffsäure als Lösungen zur Messung der Überspannung und unter Zusatz wechselnder Mengen verschiedener anorganischer und organischer Verbindungen wurde die Wasserstoffüberspannung einer Quecksilberelektrode in diesen Lösungen nach der Blasenmethode gemessen.
Revision des Atomgewichts des Dysprosiums. Analyse des Dysprosiumchlorids
Authors: Hönigschmid O. , von Welsbach Auer
Published: January 2005

Ein uns von CARL AUER VON WELSBACH zur Verfügung gestelltes Dysprosiumsulfat von hohem Reinheitsgrad, das nach röntgenspektrographischem Befund nur etwa 0,1% Ho enthielt, wodurch das gesuchte Atomgewicht nur urn 3 Einheiten der dritten Dezimale erhöht werden konnte, wurde in reines kristallisiertes Chlorid verwandelt, dieses vollständig entwässert und geschmolzen.
Über den Amphoteren Charakter des Silberhydroxyds
Authors: Laue Erich
Published: January 2005

§ 24. Die Kossel'sche Darstellung der anorganischen amphoteren Hydroxylionenverbindungen wird zu Orientierungszwecken für das ganze periodische System erweitert. Eine Folgerung dieser allgemeinen Betrachtungen wird experimentell verfolgt: die Frage, ob AgOH amphoter ist.
Zur Kenntnis der Chlorosäuren
Authors: Schwarz Robert , Meyer Georg
Published: January 2005

1. Mit Hilfe eines für Überdrucke bis zu drei Atmosphären geeigneten Tensimeters wurden die Chloride des Siliciums, Titans, Zinns, Eisens, Chroms und Aluminiums auf ihre Fähigkeit zur Anlagerung von Chlorwasserstoffsäure untersucht und so auf die Existenz freier Chlorosäuren der genannten Elemente geprüft.
Zum Verhalten des Thoroxyds in Wolframglühdrähten
Authors: Geiss W. , van Liempt J. A. M.
Published: January 2005

1. Thoroxyd in Wolframdrähten wird oberhalb 2700° absolut zu metallischem Thorium reduziert.
Zur Entstehung des Chilesalpeters
Authors: Wilke‐Dörfurt Ernst
Published: January 2005

Es wird ausgeführt, daß eine Behauptung, der natürliche Chilesalpeter sei in der Düngewirkung durch seinen Jodgehalt dem synthetischen Salpeter überlegen, so lange ungerechtfertigt erscheint, bis die Rolle des Jods im Pflanzenstoffwechsel erkannt ist, und es wird einer Hypothese STOKLASA's, die Salpeterlager seien vulkanischen Ursprungs, mit dem Hinweis auf die Größenordnung ihres Jodgehalts widersprochen.
Die Eutektische Gefrierpunktserniedrigung in binären Gemischen. Die Unabhängigkeit der eutektischen Gleichungen vom Druck
Authors: Kordes E.
Published: January 2005

Es wird gezeigt, daß die allgemeine eutektische Gleichung unabhängig vom Druck ist.
Über Ferriacetate
Authors: Krause Alfons
Published: January 2005

Es wurde das System Ferrihydrogel/Essigsäure bei 20° C eingehend untersucht und dabei folgende Beobachtungen gemacht.

I. Die Einwirkung der Essigsäure auf das Ferrihydrogel ist ein typisches Beispiel einer verzögerten chemischen Reaktion (ZSIGMONDY). Mit zunehmender Essigsäurekonzentration im Sol beobachtet man der Reihe nach Sorption (Chemosorption, Adsorption und Absorption), Peptisation und chemische Reaktion.

1. Die Sorption hat einen periodischen Verlauf, der durch aufeinanderfolgende Maxima und Minima gekennzeichnet ist. Bei einer Acidität von 0,069 n‐CH,COOH (p, = 3,05) beobachtet man ein Sorptionsminimum.

2. Die Peptisation des Ferrihydrogels tritt gleichzeitig mit der Sorption (Absorption) auf und ist am stärksten bei einer Acidität von 0,035 n bis 0,153n‐CH3COOH (von pH  etwa 3,2 bis 2,s). Bei einer Normalität von 0,7 9 n wird vollständige Peptisation erreicht.

3. Die elektrolytbildende Wirkung der Essigsäure beginnt oberhalb 0,79 n, vielleicht schon oberhalb 0,395 n. Die Umwandlung des kolloiden in kristalloides Ferriacetat ging deutlich hervor aus:

a) der dabei auftretenden koagulierenden Wirkung

b) der Farbänderung der Lösungen

c) der Änderung der Capillarisierungszahl,

d) der zunehmenden Oberflächenspannung der Lösungen.

Oberhalb der Normalität der 1,58 ist eine weitere Elektrolytbildung fraglich.
Die Anwendung von flüssigem Amalgam in der volumetrischen Analyse. X. Mehrere neue Methoden zur Bestimmung von Vanadium, Chrom und einigen Nitrokörpern
Authors: Someya Kinichi
Published: January 2005

1. Es wurden neue Amalgammethoden zur Vanadiumbestimmung ausgearbeitet, wobei solche Farbstoffe wie Safranin, Neutralrot usw. als Indicator und Jod‐ oder Kupfersulfatlösung als Titrierflüssigkeit benutzt wurden. Diese Methoden gestatten auch selektive Bestimmung des Vanadiums in Gegenwart von Eisen.
Über die Fällbarkeit der Erdsäuren durch Natriumverbindungen und die quantitative Trennung des Wolframs von Tantal und Niob
Authors: Schoeller Walter Raymond , Jahn Karl
Published: January 2005

Wenn Tantaloxyd mit Kaliumcarbonat geschmolzen und die Auflösung der Schmelze mit Chlornatrium gesättigt wird, fällt 4:3 Natriumtantalat. Nioboxyd, auf gleiche Weise behandelt, ergibt 7:6 Natrinmniobat. Die Niederschläge bilden ein schweres, weißes, mikrokristallinisches Pulver. Die Filtrate enthalten einige Milligramm Erdsäure, welche mittels Neutralisation des Carbonats zu Bicarbonat in heißer Lösung zur Ausflockung gelangen.
Über die Verwitterung des Natriumsulfits
Authors: Tarassenkow D. N.
Published: January 2005

1. Der Dampfdruck des Systems Na2SO3. 7H2O ⇋ Na2SO3, + 7H2O wurde mit indirekter Methode bei Zimmertemperatur bestimmt.
Verschiedene chemische Reaktionen bei Gegenwart lyophiler Kolloide
Authors: Ito T.
Published: January 2005

Es wurde die Reduktion von Silbernitrat bei Anwendung verschiedenster Reduktionsmittel in Gegenwart verschiedenster lyophiler Kolloide, ebenso eine größere Anzahl weiterer chemischer Vorgänge bei Gegenwart lyophiler Kolloide untersucht.
Beitrag zum Studium der Reduktion des Natriumsulfats mit Kohle
Authors: Budnikoff P. P. , Sysojeff A. N.
Published: January 2005

1. Die Erzeugung von Schwefelnatrium mittels Reduktion von Natriumsulfat mit Kohle besteht im Grunde aus folgenden drei Reaktionen:magnified image.
Über das heterogene Gleichgewicht zwischen Metallchloriden und Schwefelwasserstoff, bzw. Metallsulfiden und Chlorwasserstoff bei höheren Temperaturen
Authors: Jellinek Karl , von Podjaski Georg
Published: January 2005

1. Die Gleichgewichte der Reaktion

werden bei Cd, Mn und Ag von beiden Seiten bei mehreren Temperaturen festgestellt. Die Reaktionen sind bei Austreibung von HCl durch H2S endotherm. Es ist schon bei relativ niedrigen Temperaturen möglich, aus dem Metallchloriden mit H2S fast den gesamten Chlorwasserstoff zu verjagen.