Degradation of Three Related Bis(Pyridinium)Aldoximes in Aqueous Solutions at High Concentrations: Examples of Unexpectedly Rapid Amide Group Hydrolysis

1993 ◽  
Vol 82 (8) ◽  
pp. 782-786
Author(s):  
William D. Korte ◽  
Ming L. Shih
Keyword(s):  
Aqueous Solutions ◽  
Amide Group ◽  
High Concentrations

The metachor as a characteristic of the association of electrolytes in aqueous solutions

1984 ◽  
Vol 49 (5) ◽  
pp. 1061-1078 ◽  
Author(s):  
Jiří Čeleda ◽  
Stanislav Škramovský
Keyword(s):  
Aqueous Solutions ◽  
Apparent Volume ◽  
Solutions Of Electrolytes ◽  
Molal Volumes ◽  
The Difference ◽  
High Concentrations ◽  
Experimental Values ◽  
Suitable Characteristic ◽  
Association Of Ions ◽  
Very High

Based on the earlier paper introducing a concept of the apparent parachor of a solute in the solution, we have eliminated in the present work algebraically the effect which is introduced into this quantity by the additivity of the apparent molal volumes. The difference remaining from the apparent parachor after substracting the contribution corresponding to the apparent volume ( for which the present authors suggest the name metachor) was evaluated from the experimental values of the surface tension of aqueous solutions for a set of 1,1-, 1,2- and 2,1-valent electrolytes. This difference showed to be independent of concentration up to the very high values of the order of units mol dm-3 but it was directly proportional to the number of the free charges (with a proportionality factor 5 ± 1 cm3 mol-1 identical for all studied electrolytes). The metachor can be, for this reason, a suitable characteristic for detection of the association of ions and formation of complexes in the solutions of electrolytes, up to high concentrations where other methods are failing.

scholarly journals Investigating the Effects of Surface Adsorbates on Gold and Palladium Deposition on Carbon

2021 ◽  
Author(s):  
Bethany Bowden ◽  
Josh A. Davies-Jones ◽  
Matthew Davies ◽  
Philip R. Davies ◽  
David J. Morgan ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Ammonium Hydroxide ◽  
Ammonium Ion ◽  
Metallic State ◽  
Chloroauric Acid ◽  
Final State ◽  
Ammonium Thiosulfate ◽  
Surface Adsorbates ◽  
Surface Hydroxyls ◽  
High Concentrations

AbstractSurface functional groups have a strong influence on the deposition and final state of nanoparticles adsorbed on to the surface, a role discussed by Professor Spencer in his work. This tribute to Spencer explores the formation of hydroxyls, thiosulfates, sulfites and sulfur atoms on carbon (HOPG) surfaces and their effect on the deposition of gold and palladium from aqueous solutions. Hydroxyls formed from ammonium hydroxide treatment have identical behaviour to those formed by acid treatment, and gold adsorption from Au3+ solutions gives Au0 initially, with Au3+ formed at higher concentrations on these surfaces. In contrast, palladium adsorption is hindered by the presence of the hydroxyls and there is no indication of any reduction to the metallic state. Ammonium thiosulfate adsorbs dissociatively from aqueous solutions on HOPG if the surface is pre-activated by the presence of surface hydroxyls. At low concentrations of ammonium thiosulfate, adsorbed sulfite and sulfur are formed in equimolar concentrations whereas adsorption of high concentrations of ammonium thiosulfate gives some degree of molecular adsorption, with evidence in XP spectra for an ammonium ion and a sulfur 2p peak at 282.9 eV attributed to the undissociated thiosulfate ion. Both sulfur and the sulfite are stable at the surface in neutral solutions but the sulfite desorbs when treated with acidified solutions (~ pH ≤ 6). These two groups are also stable at 373 K but begin to desorb by 473 K. Exposure to a weak chloroauric acid solution causes the desorption of the sulfite and formation of a gold species with an XP binding energy of 84.6 eV; we cannot determine from the present data whether this peak is due to a Au(I) state or very small nanoparticles of Au(0). Graphic Abstract

scholarly journals Physico-Chemical Investigations in the Amide Group

1906 ◽  
Vol 25 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Charles E. Fawsitt
Keyword(s):  
Aqueous Solutions ◽  
Carboxylic Acids ◽  
Amide Group ◽  
Chemical Dynamics ◽  
Physico Chemical ◽  
Other Substances ◽  
The Subject

Some time ago, while studying the chemical dynamics of the changes which occur in solutions of urea or carbamide, I came upon some rather unexpected results which led me to hope that investigations conducted on somewhat the same lines with other substances of the amide group might prove to yield results of some interest. The amides referred to are those derived from carboxylic acids. While proceeding to this investigation I noticed some measurements, obtained in connection with the viscosity of aqueous solutions of carbamide, which appeared of sufficient interest to demand an inquiry into the nature of solutions of this class of substances before proceeding further with the subject of inquiry in the manner at first intended.

Absorption of Herbicides by Soybean Seeds and Their Influence on Emergence and Seedling Growth

Weed Science ◽  
1972 ◽  
Vol 20 (5) ◽  
pp. 506-510 ◽  
Author(s):  
R. E. Phillips ◽  
D. B. Egli ◽  
L. Thompson
Keyword(s):  
Acetic Acid ◽  
Aqueous Solutions ◽  
Potassium Salt ◽  
Soybean Seeds ◽  
Experimental Procedure ◽  
Low Concentrations ◽  
High Concentrations ◽  
Shoot Weight ◽  
Total Oil ◽  
Dichlorophenoxy Acetic Acid

The total quantity and concentration of six herbicides, isopropylm-chlorocarbanilate (chlorpropham), 2-chloro-4-(ethylamino)-6-(isopropylamino-s-triazine (atrazine), 3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea (linuron), 2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide (alachlor), 3-amino-2,5-dichlorobenzoic acid (chloramben), and (2,4-dichlorophenoxy)acetic acid (2,4-D), in unaerated, aqueous solutions absorbed by seeds of 11 soybean(Glycine max(L.) Merr.) strains were measured. Mechanism of movement of the herbicides from the aqueous solutions to the seeds in the experimental procedure employed was diffusion. Total quantity and concentration of herbicide found in the seeds differed significantly for both herbicides and soybean strains. Total quantity of herbicide absorbed was determined by total oil and percent oil of the seeds. The capacity of the seeds to absorb a given herbicide was more closely related to percent oil of the seeds than to total oil of the seeds. The emergence and seedling shoot weight of ‘Cutler’ soybeans were not affected appreciably by concentrations of linuron, atrazine, and chloramben (potassium salt) but were reduced by high concentrations of chlorpropham and alachlor and relatively low concentrations of 2,4-D (potassium salt) in the seeds.

DIFFUSION IN MULTICOMPONENT AQUEOUS SYSTEMS

1966 ◽  
Vol 44 (4) ◽  
pp. 477-485 ◽  
Author(s):  
J. E. Lane ◽  
J. S. Kirkaldy
Keyword(s):  
Aqueous Solutions ◽  
Relative Viscosity ◽  
Ionic Species ◽  
Aqueous Systems ◽  
Vacancy Model ◽  
High Concentrations ◽  
Substitutional Alloys ◽  
Good Agreement

A vacancy model, originally developed for the description of diffusion in substitutional alloys, is modified for application to aqueous solutions, including those containing ionic species. The results obtained with this model are similar to those of two recently published methods for estimating L-coefficients in dilute multicomponent liquid systems.Agreement with experimental L-coefficients at relatively high concentrations can be improved for this model by assuming that the jump probability of a diffusing species is inversely proportional to the relative viscosity of the mixture. Good agreement is then found for some systems up to combined solute concentrations of 3 M.

Stability of d-cycloserine in aqueous solutions at high concentrations

1971 ◽  
Vol 5 (6) ◽  
pp. 356-360 ◽  
Author(s):  
A. P. Kondrat'eva ◽  
B. P. Bruns ◽  
G. S. Libinson
Keyword(s):  
Aqueous Solutions ◽  
High Concentrations

Heat capacities and volumes of NaCl, MgCl2, CaCl2, and NiCl2 up to 6 molal in water

1981 ◽  
Vol 59 (21) ◽  
pp. 3049-3054 ◽  
Author(s):  
Gèrald Perron ◽  
Alain Roux ◽  
Jacques E. Desnoyers
Keyword(s):  
Aqueous Solutions ◽  
Long Range ◽  
Higher Order ◽  
Heat Capacities ◽  
Range Order ◽  
Long Range Order ◽  
High Concentration ◽  
Concentration Region ◽  
Partial Molar Heat Capacities ◽  
High Concentrations

It has been claimed by Enderby and co-workers that changes in long-range order occur in NiCl2 aqueous solutions at high concentrations. To investigate the possibility of a transition, the partial molar heat capacities and volumes of NiCl2, CaCl2, MgCl2, and NaCl were measured and compared in water at 25 °C up to 6 mol kg−1. In the case of NaCl, data were also measured at 5 and 45 °C. A slight change in slope of [Formula: see text] is observed for NiCl2 around 4 mol kg−1 which may suggest a third or higher order transition. However, the change is too small to support unambiguously any particular model for the high concentration region.

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