Effect of organic compounds on electrolyte chemical potential in aqueous solutions at various temperatures

1981 ◽  
Vol 59 (13) ◽  
pp. 1872-1877
Author(s):  
David M. Mohilner ◽  
Takashi Kakiuchi ◽  
Joanna Taraszewska
Keyword(s):  
Aqueous Solutions ◽  
Chemical Potential ◽  
Pure Water ◽  
Water Structure ◽  
Lead Sulfate ◽  
Glass Electrode ◽  
Liquid Junction ◽  
Emf Measurements ◽  
Different Temperatures ◽  
Lead Amalgam

Data are reported on the concentration of Na2SO4 required to hold its chemical potential equal to its value in a 0.10045 m solution in pure water for aqueous solutions containing 2-butanol and 1-propanol at six different temperatures. The data were obtained from emf measurements on a galvanic cell without liquid junction containing a sodium reversible glass electrode and a 2-phase lead amalgam – lead sulfate electrode. The results of the measurements are interpreted in terms of the water structure making properties of the organic compound.

Effects of solvent structure on electron reactivity and radiolysis yields: 2-propanol/water mixed solvents

1984 ◽  
Vol 62 (7) ◽  
pp. 1265-1270 ◽  
Author(s):  
Joanna Cygler ◽  
Gordon R. Freeman
Keyword(s):  
Pure Water ◽  
Mixed Solvents ◽  
Water Structure ◽  
Trap Depth ◽  
Solvent Structure ◽  
Solvated Electrons ◽  
Absorption Energy ◽  
Diffusion Controlled ◽  
Free Ion ◽  
Different Temperatures

Reaction of solvated electrons with nitrobenzene, N, is nearly diffusion controlled in both pure solvents; kN ~ 1010 dm3/mol s. The value of kN is approximately proportional to the inverse viscosity η−1 in the pure solvents, and in the mixed solvents at different temperatures. However, on going from zero to 74 mol% water at the same temperature kN is independent of the 40% increase of η. Electron diffusion in the mixed solvents is not a simple function of fluidity.Reaction with the inefficient scavengers tryptophane (kS ~ 109 dm3/mol s) and phenol (kS ~ 107–108 dm3/mol s) correlates inversely with the electron optical absorption energy. The latter is related to the trap depth in the solvent; electrons in deeper traps have less tendency to react with molecules of low electron affinity.Addition of 3 mol% 2-PrOH to water at 296 K increases the value of Gεmax by 16%, although the value in pure 2-PrOH is three-fold smaller than that in pure water. The increase is attributed to an increase in the free ion yield, caused by an increase in the product of the electron thermalization range and the microscopic dielectric constant of the fluid between the ion and electron, averaged over the time that they exist as a correlated pair. Addition of a small amount of alcohol to water increases the orderliness of the water structure.

scholarly journals Behavior and properties of water in silicate melts under deep mantle conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bijaya B. Karki ◽  
Dipta B. Ghosh ◽  
Shun-ichiro Karato
Keyword(s):  
Electrical Conductivity ◽  
Molar Volume ◽  
Water Solution ◽  
Pure Water ◽  
Electrical Conductance ◽  
Water Structure ◽  
Bulk Water ◽  
Silicate Melts ◽  
Pressure Regime ◽  
Low Pressures

AbstractWater (H2O) as one of the most abundant fluids present in Earth plays crucial role in the generation and transport of magmas in the interior. Though hydrous silicate melts have been studied extensively, the experimental data are confined to relatively low pressures and the computational results are still rare. Moreover, these studies imply large differences in the way water influences the physical properties of silicate magmas, such as density and electrical conductivity. Here, we investigate the equation of state, speciation, and transport properties of water dissolved in Mg1−xFexSiO3 and Mg2(1−x)Fe2xSiO4 melts (for x = 0 and 0.25) as well as in its bulk (pure) fluid state over the entire mantle pressure regime at 2000–4000 K using first-principles molecular dynamics. The simulation results allow us to constrain the partial molar volume of the water component in melts along with the molar volume of pure water. The predicted volume of silicate melt + water solution is negative at low pressures and becomes almost zero above 15 GPa. Consequently, the hydrous component tends to lower the melt density to similar extent over much of the mantle pressure regime irrespective of composition. Our results also show that hydrogen diffuses fast in silicate melts and enhances the melt electrical conductivity in a way that differs from electrical conduction in the bulk water. The speciation of the water component varies considerably from the bulk water structure as well. Water is dissolved in melts mostly as hydroxyls at low pressure and as –O–H–O–, –O–H–O–H– and other extended species with increasing pressure. On the other hand, the pure water behaves as a molecular fluid below 15 GPa, gradually becoming a dissociated fluid with further compression. On the basis of modeled density and conductivity results, we suggest that partial melts containing a few percent of water may be gravitationally trapped both above and below the upper mantle-transition region. Moreover, such hydrous melts can give rise to detectable electrical conductance by means of electromagnetic sounding observations.

Kinetics and thermodynamics of the sorption of furaltadone from aqueous solutions on magnetic multi-walled carbon nanotubes

2014 ◽  
Vol 70 (6) ◽  
pp. 964-971
Author(s):  
Xu Chen ◽  
Zhen-hu Xiong
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solutions ◽  
Sorption Data ◽  
Multi Wall Carbon Nanotubes ◽  
Adsorption Behaviors ◽  
Different Temperatures ◽  
Multi Walled Carbon Nanotubes ◽  
Pseudo Second Order ◽  
Experimental Data Analysis ◽  
Walled Carbon Nanotubes

Magnetic multi-wall carbon nanotubes (M-MWCNTs) were used as an adsorbent for removal of furaltadone from aqueous solutions, and the adsorption behaviors were investigated by varying pH, sorbent amount, sorption time and temperature. The results showed that the adsorption efficiency of furaltadone reached 97% when the dosage of M-MWCNT was 0.45 g · L−1, the pH was 7 and the adsorption time was 150 min. The kinetic data showed that the pseudo-second-order model can fit the adsorption kinetics. The sorption data could be well explained by the Langmuir model under different temperatures. The adsorption process was influenced by both intraparticle diffusion and external mass transfer. The experimental data analysis indicated that the electrostatic attraction and π–π stacking interactions between M-MWCNT and furaltadone might be the adsorption mechanism. Thermodynamic analysis reflected that adsorption of furaltadone on the M-MWCNT was spontaneous and exothermic. Our study showed that M-MWCNTs can be used as a potential adsorbent for removal of furaltadone from water and wastewater.

Motions of water molecules in dilute aqueous solutions of tertiary butyl alcohol; a neutron scattering study of hydrophobic hydration

1970 ◽  
Vol 319 (1537) ◽  
pp. 189-208 ◽  
Keyword(s):  
Aqueous Solutions ◽  
Water Structure ◽  
Hydrophobic Hydration ◽  
Step Length ◽  
Solute Concentration ◽  
Butyl Alcohol ◽  
Tertiary Butyl ◽  
Self Diffusion ◽  
Dilute Aqueous Solutions ◽  
Neutron Scattering Study

Cold neutron inelastic scattering experiments have been performed on dilute aqueous solutions of (CD 3 ) 3 COH and of solutions of (CH 3 ) 3 COH in D 2 O at 21 °C. From the broadening of the quasi-elastic peak and independently determined self-diffusion coefficients ( D ), diffusive lifetimes ( c ) of H 2 O molecules have been calculated as functions of solute concentration. The product Dc is insensitive to concentration, giving a mean diffusion step length of 0.14 nm. The inelastic portion of the spectrum, reflecting lattice-like hydrogen bonding modes indicates that the solute enhances the water ‘structure’ but that such structure bears no resemblance to ice.

scholarly journals Valorization of Spent Coffee by Caffeine Extraction Using Aqueous Solutions of Cholinium-Based Ionic Liquids

2021 ◽  
Vol 13 (13) ◽  
pp. 7509
Author(s):  
Ana M. Ferreira ◽  
Hugo M. D. Gomes ◽  
João A. P. Coutinho ◽  
Mara G. Freire
Keyword(s):  
Ionic Liquids ◽  
Aqueous Solutions ◽  
Pure Water ◽  
Waste Product ◽  
Weight Ratio ◽  
Extraction Yield ◽  
Operational Conditions ◽  
Coffee Grounds ◽  
Extractable Compounds ◽  
Nutraceutical Products

Spent coffee grounds (SCGs) are a waste product with no relevant commercial value. However, SCGs are rich in extractable compounds with biological activity. To add value to this coffee byproduct, water and aqueous solutions of cholinium-based ionic liquids (ILs) were studied to extract caffeine from SCGs. In general, all IL aqueous solutions lead to higher extraction efficiencies of caffeine than pure water, with aqueous solutions of cholinium bicarbonate being the most efficient. A factorial planning was applied to optimize operational conditions. Aqueous solutions of cholinium bicarbonate, at a temperature of 80 °C for 30 min of extraction, a biomass–solvent weight ratio of 0.05 and at an IL concentration of 1.5 M, made it possible to extract 3.29 wt% of caffeine (against 1.50 wt% obtained at the best conditions obtained with pure water). Furthermore, to improve the sustainability of the process, the same IL aqueous solution was consecutively applied to extract caffeine from six samples of fresh biomass, where an increase in the extraction yield from 3.29 to 13.10 wt% was achieved. Finally, the cholinium bicarbonate was converted to cholinium chloride by titration with hydrochloric acid envisioning the direct application of the IL-caffeine extract in food, cosmetic and nutraceutical products. The results obtained prove that aqueous solutions of cholinium-based ILs are improved solvents for the extraction of caffeine from SCGs, paving the way for their use in the valorization of other waste rich in high-value compounds.

Effect of Sodium Sulphate on the Volumetric, Rheological and Refractometric Properties of some Disaccharides in Aqueous Solutions at Different Temperatures

2008 ◽  
Vol 222 (1) ◽  
pp. 177-204 ◽  
Author(s):  
Parampaul Kaur Banipal ◽  
Harpreet Singh Dhanjun ◽  
Suman Sharma ◽  
Harneet Hundal ◽  
Tarlok Singh Banipal
Keyword(s):  
Aqueous Solutions ◽  
Sodium Sulphate ◽  
Different Temperatures

Ion solvation and water structure in potassium halide aqueous solutions

2006 ◽  
Vol 124 (3) ◽  
pp. 180-191 ◽  
Author(s):  
Alan K. Soper ◽  
Kristian Weckström
Keyword(s):  
Aqueous Solutions ◽  
Water Structure ◽  
Ion Solvation ◽  
Potassium Halide

Investigation of Extraction and Collection of Polycyclic Aromatic Hydrocarbons from Aqueous Solutions at Different Temperatures

2017 ◽  
Vol 40 (1) ◽  
pp. 40-49 ◽  
Author(s):  
Rejane S. Cargnin ◽  
Paulo C. do Nascimento ◽  
Luis M. Ferraz ◽  
Márcia M. Barichello ◽  
Letícia C. Brudi ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aqueous Solutions ◽  
Aromatic Hydrocarbons ◽  
Different Temperatures ◽  
Polycyclic Aromatic
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