Isentropic compressibilities of electrolytes in acetonitrile at 25 °C

1981 ◽  
Vol 59 (14) ◽  
pp. 2212-2217 ◽  
Author(s):  
Isobel Davidson ◽  
Gérald Perron ◽  
Jacques E. Desnoyers
Keyword(s):  
General Formula ◽  
Free Space ◽  
Infinite Dilution ◽  
Inorganic Ions ◽  
The Other ◽  
Square Root ◽  
Isentropic Compressibilities ◽  
Ionic Size ◽  
Acetonitrile Solutions ◽  
Solvent Molecules

The sound velocities of some 1:1 electrolytes in acetonitrile were measured by the "sing around" method. Apparent molal isentropic compressibilities [Formula: see text] of the electrolytes were derived from these data and from previously determined densities. Infinite dilution partial molal compressibilities [Formula: see text] were obtained by extrapolation from the plot [Formula: see text] against the square-root of the molality. Approximate ionic values are obtained on the assumption that [Formula: see text] In general, [Formula: see text] of inorganic ions are much more negative in acetonitrile than in water and, except for Li+, show little dependence on ionic size. On the other hand, [Formula: see text] of tetraalkylammonium bromides become increasingly positive as the size of the cations increases. This is again in contrast with [Formula: see text] of these electrolytes in water which remain negative. These large positive values arise from the free space between the ions and the solvent molecules, which is large in acetonitrile solutions.

Heat capacities and isentropic compressibilities of electrolytes in propylene carbonate at 25 °C

1987 ◽  
Vol 65 (6) ◽  
pp. 1402-1406 ◽  
Author(s):  
Gérald Perron ◽  
Guylaine Trudeau ◽  
Jacques E. Desnoyers
Keyword(s):  
Propylene Carbonate ◽  
Infinite Dilution ◽  
Alkali Halides ◽  
Heat Capacities ◽  
Apparent Molar Heat Capacities ◽  
Solvent Interactions ◽  
Isentropic Compressibilities ◽  
Ionic Size ◽  
Tetraalkylammonium Halides ◽  
Heat Capacities Of Electrolytes

The heat capacities per unit volume and sound velocities of many solutions of 1:1 electrolytes in propylene carbonate (PC) were measured at 25 °C. Combining these data with previously published densities, apparent molar heat capacities and isentropic compressibilities were calculated. By extrapolation to infinite dilution, the corresponding standard partial molar quantities were obtained. The heat capacities and compressibilities of water in PC were also calculated. Through ionic additivity, it was possible to calculate these functions for all alkali and tetraalkylammonium halides. The magnitude and trends with ionic size of the heat capacities of electrolytes in PC are similar to those in other aprotic solvents such as acetonitrile (ACN) and dimethylformamide (DMF) and significantly different from those in water. On the other hand, with compressibilities, the magnitudes sssssssare the same in PC and in water for alkali halides but significantly different for tetraalkylammonium halides. The trends with ionic size are similar to those in ACN. These effects can be interpreted through ion–solvent interactions. The separation of these thermodynamic functions into their ionic contributions is also discussed.

scholarly journals The Dissociation of the Compound of Iodine and Thio-urea

1904 ◽  
Vol 24 ◽  
pp. 233-239 ◽  
Author(s):  
Hugh Marshall
Keyword(s):  
Nitric Acid ◽  
General Formula ◽  
Free Acid ◽  
The Other ◽  
Image Position

When thio-urea is treated with suitable oxidising agents in presence of acids, salts are formed corresponding to the general formula (CSN2H4)2X2:—Of these salts the di-nitrate is very sparingly soluble, and is precipitated on the addition of nitric acid or a nitrate to solutions of the other salts. The salts, as a class, are not very stable, and their solutions decompose, especially on warming, with formation of sulphur, thio-urea, cyanamide, and free acid. A corresponding decomposition results immediately on the addition of alkali, and this constitutes a very characteristic reaction for these salts.

Solvation effects on the conductivity of concentrated electrolyte solutions

1976 ◽  
Vol 54 (18) ◽  
pp. 2953-2966 ◽  
Author(s):  
Douglas E. Goldsack ◽  
Raymond Franchetto ◽  
Arlene (Anttila) Franchetto
Keyword(s):  
Activity Coefficient ◽  
Alkali Halide ◽  
Infinite Dilution ◽  
Electrolyte Solutions ◽  
Molar Conductance ◽  
The Other ◽  
Solvation Number ◽  
Parameter Equation ◽  
Conductance Data ◽  
Halide Salts

The Falkenhagen–Leist–Kelbg equation for the conductivity of electrolyte solutions has been extended to include the effect of solvation on the concentration of the salt. Two equations have been derived, both of which have only two freely adjustable parameters at any temperature: Λ0 the molar conductance of the salt at infinite dilution and H0, a solvation number parameter for the salt. In one of these equations H0 is assumed to be independent of concentration. In the other, H0 is assumed to be dependent on concentration and an explicit concentration dependent formula is derived for H0. Conductance data for the alkali halide salts in the 0.5 to 10 m concentration range and 0 to 60 °C temperature range were found to be adequately reproduced by both these equations, but with the variable hydration parameter equation yielding better fits to the data. The H0 parameters from the fixed hydration parameter equation are found to be similar to those obtained from the analysis of activity coefficient and other data whereas the variable hydration parameter equation yields H0 parameters which are much larger.

scholarly journals Decachlorocyclopentasilanes coordinated by pairs of chloride anions, with different cations, but the same solvent molecules

2017 ◽  
Vol 73 (12) ◽  
pp. 1903-1907 ◽  
Author(s):  
Maximilian Moxter ◽  
Julian Teichmann ◽  
Hans-Wolfram Lerner ◽  
Michael Bolte ◽  
Matthias Wagner
Keyword(s):  
Crystal Structures ◽  
General Position ◽  
Rotation Axis ◽  
Chloride Ion ◽  
The Other ◽  
Structural Motif ◽  
Solvent Molecules

We have determined the crystal structures of two decachlorocyclopentasilanes, namely bis(tetra-n-butylammonium) dichloride decachlorocyclopentasilane dichloromethane disolvate, 2C16H36N+·2Cl−·Si5Cl10·2CH2Cl2, (I), and bis(tetraethylammonium) dichloride decachlorocyclopentasilane dichloromethane disolvate, 2C8H20N+·2Cl−·Si5Cl10·2CH2Cl2, (II), both of which crystallize with discrete cations, anions, and solvent molecules. In (I), the complete decachlorocyclopentasilane ring is generated by a crystallographic twofold rotation axis. In (II), one cation is located on a general position and the other two are disordered about centres of inversion. These are the first structures featuring the structural motif of a five-membered cyclopentasilane ring coordinated from both sides by a chloride ion. The extended structures of (I) and (II) feature numerous C—H...Cl interactions. In (II), the N atoms are located on centres of inversion and as a result, the ethylene chains are disordered over equally occupied orientations.

Density estimates of binary aqueous solutions

1983 ◽  
Vol 48 (8) ◽  
pp. 2327-2334
Author(s):  
Otakar Söhnel ◽  
Petr Novotný ◽  
Zdeněk Šolc
Keyword(s):  
Aqueous Solutions ◽  
Molar Volume ◽  
Partial Molar Volume ◽  
Infinite Dilution ◽  
The Other ◽  
Density Estimates ◽  
Molar Volumes ◽  
Solutions Of Electrolytes ◽  
Experimental Values

Two methods are given for assessment of density of binary aqueous solutions of electrolytes; one is based on partial molar volume of the dissolved electrolyte at infinite dilution, and the other is based on additivity of apparent molar volumes at a given concentration. The density estimates of aqueous solutions by means of the two methods are compared with experimental values for some electrolytes of the type 1-1 to 4 and 2-2. In all cases the estimates agree with experimental densities up to concentrations of the saturated solutions.

scholarly journals Efficacy of Fungicide Applications During and After Anthesis Against Fusarium Head Blight and Deoxynivalenol in Soft Red Winter Wheat

Plant Disease ◽  
2014 ◽  
Vol 98 (10) ◽  
pp. 1387-1397 ◽  
Author(s):  
D. L. D'Angelo ◽  
C. A. Bradley ◽  
K. A. Ames ◽  
K. T. Willyerd ◽  
L. V. Madden ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Fusarium Head Blight ◽  
Field Experiments ◽  
The Other ◽  
Square Root ◽  
Head Blight ◽  
Soft Red Winter Wheat ◽  
Untreated Check ◽  
Red Winter Wheat ◽  
Days After Anthesis

Seven field experiments were conducted in Ohio and Illinois between 2011 and 2013 to evaluate postanthesis applications of prothioconazole + tebuconazole and metconazole for Fusarium head blight and deoxynivalenol (DON) control in soft red winter wheat. Treatments consisted of an untreated check and fungicide applications made at early anthesis (A), 2 (A+2), 4 (A+4), 5 (A+5), or 6 (A+6) days after anthesis. Six of the seven experiments were augmented with artificial Fusarium graminearum inoculum, and the other was naturally infected. FHB index (IND), Fusarium damaged kernels (FDK), and DON concentration of grain were quantified. All application timings led to significantly lower mean arcsine-square-root-transformed IND and FDK (arcIND and arcFDK) and log-transformed (logDON) than in the untreated check; however, arcIND, arcFDK, and logDON for the postanthesis applications were generally not significantly different from those for the anthesis applications. Relative to the check, A+2 resulted in the highest percent control for both IND and DON, 69 and 54%, respectively, followed by A+4 (62 and 52%), A+6 (62 and 48%), and A (56 and 50%). A+2 and A+6 significantly reduced IND by 30 and 14%, respectively, relative to the anthesis application. Postanthesis applications did not, however, reduce DON relative to the anthesis application. These results suggest that applications made up to 6 days following anthesis may be just as effective as, and sometimes more effective than, anthesis applications at reducing FHB and DON.

Compressibilités de l'eau et du benzène dans tout le domaine de miscibilité du système eau + 2-propanol + benzène

1989 ◽  
Vol 67 (6) ◽  
pp. 953-958
Author(s):  
Daniel Hétu ◽  
Jaime Lara ◽  
Jacques E. Desnoyers
Keyword(s):  
Phase Diagram ◽  
Ternary System ◽  
Infinite Dilution ◽  
Intermediate Region ◽  
Rich Region ◽  
Isentropic Compressibilities ◽  
Inverse Micelles ◽  
Mixed Aggregates ◽  
Apparent Molar Compressibilities ◽  
Sound Velocities

Sound velocities have been measured over the whole miscibility domain of the water + 2-propanol + benzene system. The apparent molar isentropic compressibilities of benzene and water were calculated from these data. The apparent molar compressibilities of benzene and water present large changes in the water-rich and benzene-rich regions, respectively, whereas the changes are smooth in the intermediate region. These results suggest that microtransitions similar to the formation of micelles and inverse micelles occur at the two ends of the phase diagram. The regularity of the intermediate region is consistent with a bicontinuous model of microemulsions. For the water-rich region, the compressibilities of transfer of benzene at infinite dilution, from water to water + 2-propanol mixtures, were simulated with the model of Roux and co-workers. This simulation tends to confirm that the alcohol and the benzene form mixed aggregates. Keywords: compressibility, ternary system, microemulsion, water, benzene, 2-propanol.

scholarly journals FPGA-Based Synthesis of High-Speed Hybrid Carry Select Adders

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
V. Kokilavani ◽  
K. Preethi ◽  
P. Balasubramanian
Keyword(s):  
High Speed ◽  
Boolean Logic ◽  
The Other ◽  
Square Root ◽  
Verilog Hdl ◽  
Other Hand ◽  
Carry Select Adder

Carry select adder is a square-root time high-speed adder. In this paper, FPGA-based synthesis of conventional and hybrid carry select adders are described with a focus on high speed. Conventionally, carry select adders are realized using the following: (i) full adders and 2 : 1 multiplexers, (ii) full adders, binary to excess 1 code converters, and 2 : 1 multiplexers, and (iii) sharing of common Boolean logic. On the other hand, hybrid carry select adders involve a combination of carry select and carry lookahead adders with/without the use of binary to excess 1 code converters. In this work, two new hybrid carry select adders are proposed involving the carry select and section-carry based carry lookahead subadders with/without binary to excess 1 converters. Seven different carry select adders were implemented in Verilog HDL and their performances were analyzed under two scenarios, dual-operand addition and multioperand addition, where individual operands are of sizes 32 and 64-bits. In the case of dual-operand additions, the hybrid carry select adder comprising the proposed carry select and section-carry based carry lookahead configurations is the fastest. With respect to multioperand additions, the hybrid carry select adder containing the carry select and conventional carry lookahead or section-carry based carry lookahead structures produce similar optimized performance.

The ontology of person-centered healthcare: Theoretical essentials to reground medicine within its humanistic framework. Part I - A centered concept of personhood: Some tools to conceptualise subjectivity

2018 ◽  
Vol 6 (1) ◽  
pp. 146
Author(s):  
Thomas Frölich ◽  
F F Bevier ◽  
Alicja Babakhani ◽  
Hannah H Chisholm ◽  
Peter Henningsen ◽  
...  
Keyword(s):  
Graph Theory ◽  
Free Space ◽  
Rooted Tree ◽  
The Other ◽  
Discrete Mathematics ◽  
Soap Bubble ◽  
Soap Bubbles ◽  
In Series ◽  
The One ◽  
Individual Trees

To address subjectivity, as a generally rooted phenomenon, other ways of visualisation must be applied than in conventional objectivistic approaches. Using ‘trees’ as operational metaphors, as employed in Arthur Cayley’s ‘theory of the analytical forms called trees’, one rooted ‘tree’ must be set beneath the other and, if such ‘trees’ are combined, the resulting ‘forest’ is nevertheless made up of individual ‘trees’ and not of a deconstructed mix of ‘roots’, ‘branches’, ‘leaves’ or further categories, each understood as addressable both jointly and individually. The reasons for why we have chosen a graph theory and corresponding discrete mathematics as an approach and application are set out in this first of our three articles. It combines two approaches that, in combination, are quite uncommon and which are therefore not immediately familiar to all readers. But as simple as it is to imagine a tree, or a forest, it is equally simple to imagine a child blowing soap bubbles with the aid of a blow ring. A little more challenging, perhaps, is the additional idea of arranging such blow rings in series, transforming the size of the soap bubble in one ring after the other. To finally combine both pictures, the one of trees and the other of blow rings, goes beyond simple imagination, especially when we prolong the imagined blow ring becoming a tunnel, with a specific inner shape. The inner shape of the blow ring and its expansion as a tunnel are understood as determined by discrete qualities, each forming an internal continuity, depicted as a scale, with the scales combined in the form of a glyph plot. The different positions on these scales determine their length and if the endpoints of the spines are connected with an enveloping line then this corresponds to the free space left open in the tunnel to go through it. Using so many visualisation techniques at once is testing. Nevertheless, this is what we propose here and to facilitate such a visualisation within the imagination, we do it step by step. As the intended result of this ‘juggling of three balls’, as it were, we end up with a concept of how living beings elaborate their principal structure to enable controlled outside-inside communication.

scholarly journals XI. On the normal paraffins. Part III

1879 ◽  
Vol 29 (196-199) ◽  
pp. 364-365
Keyword(s):  
Hydrochloric Acid ◽  
General Formula ◽  
The Other ◽  
Partial Decomposition ◽  
Lower Temperature

The isomeric monochlorides, obtained from the normal paraffins existing in petroleum, yield by the abstraction of hydrochloric acid a mixture of olefines, one portion of which readily combines with hydrochloric acid in the cold, whilst the other unites with it only on heating. The chlorides formed in the cold boil with partial decomposition and at a lower temperature than the others, which distil without undergoing any change, and have the general formula CH 3 - CHCl—C n H 2 n +1 .

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