Solubility Of Sodium Chloride Research Articles

Thermodynamics of NaCl in dense water vapor via cross virial coefficients

Sodium chloride in the fluid phase is important for the chemistry of natural hydrothermal processes in the Earth’s crust and derived industrial utilizations, where thermodynamics is an essential part that can also to some extent fill in missing experimental data. The solubility of sodium chloride in crystalline form (halite) in water vapor is modeled using a novel combination of an accurate equation of state for pure water and a truncated virial equation for water mixed with sodium chloride. In the resulting Helmholtz energy expression, interactions between H2O and NaCl are incorporated through the second (B12), third (C112), and fourth (D1112) cross virial coefficients. The temperature dependence of the coefficients has been determined by regression to experimental data. Specifically, the temperature dependence of B12 is assumed to follow that of a square-well gas, whereas C112 and D1112 are calculated using purely exponential functions of inverse temperature. The temperature dependence of B12 is supported by independent calculations of ab initio interaction energies between H2O and NaCl. For water itself, all terms in the virial equation are collectively modeled by the IAPWS-95 equation of state. For sodium chloride, interactions between two or more NaCl molecules are disregarded. The model shows quantitative agreement with available solubility data in the vapor–halite coexistence region, which implies that the water vapor density is approximately less than 130kgm−3. Its theoretical basis ensures that predictions are reliable in regions where experimental data are missing. The direct calculation of cross virial coefficients is overall useful for modeling geochemical fluids with low solute concentrations, including systems with multiple solvents.

Exploring detailed microcosmic mechanisms of sodium chloride deposition in supercritical water reactors from the aspect of solvation structure: A combination of MD and QM simulations

The dissolution characteristics and microscopic dissolution process of salt in supercritical water (SCW) are the fundamental influence of scale formation. In this paper, molecular dynamics (MD) and quantum mechanics (QM) were used to study the solubility and solvation structure of sodium chloride in supercritical water. The potential mean force (PMF), radial distribution function (RDF) and coordination number (CN) indicate that the solubility of sodium chloride in SCW decreases with the increase of temperature and the decrease of density. As the system density decreases from 0.3 g/cm3 to 0.1 g/cm3 and the temperature increases from 600 K to 900 K, the CN of water molecules in the solvation shell decreases from 2.89 to 1.01, which is consistent with the trend of the experimental results. The electrostatic potential distribution and intermolecular interaction of the solvation shell around Na+ were obtained by QM method. The solution free energy of Na+–3H2O in implicit solvent was obtained. In the condition range of this study, when the temperature is the lowest and the dielectric constant is the largest, the free energy of dissolution is the smallest, which is −0.0991 a.u. This study will lay a foundation for the study of salt deposition in SCW.

Effect of The Number of Hydroxyls and Carbons on the Solubility of Sodium Chloride in Alcohol and The Electropolishing Behavior of Ti-6Al-4V Alloy in Alcohol-Salt System

Ethylene glycol-sodium chloride (NaCl) is an environmentally friendly electrolyte in the electropolishing of titanium. To better understand the effect of the alcohol on the electropolishing of titanium, the solubility of NaCl in different alcohols and the electropolishing of titanium with different mixtures have been systematically investigated. The results reveal that the solubility of NaCl increases with the increase of hydroxyls (-OH), but decreases with the increase of carbons (C) in alkyl (-R). Moreover, the conductivity of the electrolyte increases both as the increasing of NaCl concentration and temperature, and methanol, 1,2-propanediol, and glycerol-NaCl electrolytes could be also selected as candidates for further electropolishing titanium group metals.

Experimental Determination and Modeling of the Solubility of Sodium Chloride in Subcritical Water from (568 to 598) K and (10 to 25) MPa

The solubility of sodium chloride was investigated by using a continuous flow method over the temperature and pressure ranges of (568 to 598) K and (10 to 25) MPa, respectively. The results showed that the solubility of sodium chloride increased with increasing water density. In general, over the low-density ranges, the increase of solubility is not significant. Whereas, over the high-density ranges, the solubility greatly increases with density. The experimental solubility data were also correlated with seven empirical and semiempirical models (empirical, enthalpy, Cp-, Flory–Huggins, ionization, second-order polynomial, and third-order polynomial models). The correlated results indicated that the second-order polynomial model provided the best fit. The solubility data of sodium chloride in sub-, near-, and supercritical water from this work and literature were collected with a view to evaluating the correlative and predictive capability of these models over a wide range. The enthalpy model gave the best...

Solubility of sodium chloride in phosphonium-based deep eutectic solvents

The solubility of sodium chloride (NaCl) in several phosphonium-based deep eutectic solvents (DESs) is studied in this work. Seven combinations of DESs were investigated. The solubility of NaCl increased with temperature in all DESs at all combinations. The type of salt and hydrogen bond donor (HBD) and the salt:HBD mole ratio of the DES affected the solubility of NaCl. The solubility of NaCl in DESs that use ethylene glycol or glycerol (neutral molecules) as HBDs is very low in comparison to DESs that use zinc (II) chloride (ZnCl2) or ferric (III) chloride (FeCl3) which are metal halides as complexing agents. DESs containing ZnCl2 produced the highest solubility. Ethyltriphenylphosphonium bromide:ZnCl2 DES possessed a NaCl solubility of 88.500wt.% at 111°C, and tetrabutylphosphonium bromide:ZnCl2 DES possessed NaCl solubilities of 70.120wt.% and 75.000wt.% at 100°C and 160°C, respectively. The thermodynamic activity coefficient non-random two-liquid (NRTL) model was used to correlate the solubility of NaCl in the studied DESs. The calculated values in some DESs showed satisfactory agreement with the experimental values.

Solubility of Sodium Salts in Ammonium-Based Deep Eutectic Solvents

The solubility of sodium chloride (NaCl), sodium bromide (NaBr), and sodium carbonate (Na2CO3) was measured in nine ammonium-based deep eutectic solvents (DESs). The aim of the study is to assess the potential use of these DESs as solvents and electrolytes for the separation of sodium metal from its salts. The studied DESs were prepared by combining ammonium salts with various hydrogen-bond donors (HBDs) or metal halides. It was found that the solubility of the sodium salts in DESs increases with temperature in many cases. The maximum solubility of NaCl achieved was 100 w = 80 in N,N-diethylethanolammonium chloride:zinc(II) chloride (molar ratio 1:3) at 90 °C. In addition, the solubility of the sodium salts was modeled successfully using the non-random two liquid (NRTL) model.

A simple and fast procedure for in situ determination of water in ethanol fuel

A simple and inexpensive procedure, based on the high difference in solubility of sodium chloride in ethanol and water, is proposed to estimate the water content in ethanol fuel. The ionic concentration of solutions saturated with the salt is monitored by conductometric measurements with a linear response up to 16% water in an alcoholic medium and a limit of detection of 0.05% (v/v). The procedure is precise (coefficient of variation of 0.6%, n = 10) and accurate (results in agreement with those obtained by Karl Fischer amperometric titration at the 95% confidence level). An indicating electronic device exploiting the same principle was proposed for in situ monitoring of ethanol fuel samples aiming at the fast detection of unconformities. The device can be operated by nonexperts, generating a binary response indicated by coloured LEDs, and it successfully classified commercial samples spiked with different amounts of water.

A Simple and Fast Procedure forin situDetermination of Water in Ethanol Fuel

A simple and inexpensive procedure, based on the high difference in solubility of sodium chloride in ethanol and water, is proposed to estimate the water content in ethanol fuel. The ionic concentration of solutions saturated with the salt is monitored by conductometric measurements with a linear response up to 16% water in an alcoholic medium and a limit of detection of 0.05% (v/v). The procedure is precise (coefficient of variation of 0.6%, n = 10) and accurate (results in agreement with those obtained by Karl Fischer amperometric titration at the 95% confidence level). An indicating electronic device exploiting the same principle was proposed for in situ monitoring of ethanol fuel samples aiming at the fast detection of unconformities. The device can be operated by nonexperts, generating a binary response indicated by coloured LEDs, and it successfully classified commercial samples spiked with different amounts of water.

The Effect of Magnetic Field on The Solubility of NaCl and CaCl2.2H2O at Different Temperature and pH Values

The electrical conductivity (E.C.) changes of a certain concentration (1000ppm) of aqueous sodium chloride and calcium chloride dihydrate solutions as a function to the solubility with and without applying a multiple constant magnetic field at different temperature and pH values were studied. A magnetic funnel with a magnetic field power of 450 gauss was used to prepare the magnetic water by passing the later 1, 5 and 10 times with flow rate of 41.66 mL/sec, before dissolving the sodium chloride and calcium chloride dihydrate salts. There was a proportional relationship between the solubility of sodium chloride and calcium chloride dihydrate and the number of water exposure to the magnetic field. There was also a proportional relationship between the electrical conductivity records and the increasing in temperature and pH values. It was found that the increasing in pH value is more effective as compared with the elevation in temperature degree. In general, the magnetic solutions of sodium chloride and calcium chloride dihydrate showed highly electrical conductivity values as compared with non-magnetic solutions. It was clear, that the advantages from using magnetized solutions of these two salts will be useful in the biological and physiological systems.

Fundamental salt and water transport properties in directly copolymerized disulfonated poly(arylene ether sulfone) random copolymers

Water and sodium chloride solubility, diffusivity and permeability in disulfonated poly(arylene ether sulfone) (BPS) copolymers were measured for both acid and salt form samples at sulfonation levels from 20 to 40 mol percent. The hydrophilicity of these materials, based on water uptake, increased significantly as sulfonation level increased. The water permeability of BPS materials in both the salt and acid forms increases more than one order of magnitude as sulfonation level increases from 20% to 40%, while NaCl permeability increases by two orders of magnitude. The water and salt diffusivity and permeability were correlated with water uptake, consistent with expectations from free volume theory. In addition, a tradeoff was observed between water/salt solubility, diffusivity, and permeability selectivity and water solubility, diffusivity and permeability, respectively. This finding suggests a water/salt permeability/selectivity tradeoff, similar to that operative in gas separation polymers, in this family of polymers.

Solubility of sodium chloride in water under high pressure

The solubility ( m sat) of sodium chloride in water was measured in the pressure range 0.10–300 MPa, and temperatures from 263 to 313 K. In the region of high temperature and low pressure, the solubility values of NaCl anhydride obtained were fitted to the equation ln[ m sat( p, T)/mol kg −1] = 2.86623 − 571.361/( T/K) + 77,128/( T/K) 2 + 4.0479 × 10 −4( p/MPa) − 7.445 × 10 −7( p/MPa) 2 + 6.209 × 10 −10( p/MPa) 3 with a standard deviation of 0.08%. In the low-temperature and high-pressure region, the values for NaCl·2H 2O were fitted to ln[ m sat( p, T)/mol kg −1] = 5.35183 − 1366.040/( T/K) + 108,664/( T/K) 2 + [0.010331 − 5.8869( T/K) −1 + 831.7( T/K) −2]( p/MPa) with a standard deviation of 0.14%. The experimental values of the high-pressure solubilities were compared with thermodynamic estimates using density data of the solid and aqueous solution of sodium chloride and the activity coefficient of the aqueous solution.

Influence of Properties of Nonaqueous Solvents on the Solubility of NH4Cl and Thermodynamics of Its Solution

The solubility of ammonium chloride in acetonitrile, dioxane, and 2-propanol in the range 298.15–338.15 K was determined using 36Cl tracer. The influence of properties of nonaqueous solvents on the solubility of ammonium, potassium, and sodium chlorides was subjected to thermodynamic and correlation analysis. The low solubility of ammonium chloride in dioxane and acetonitrile is due to the endothermic effect, and its high solubility in 2-propanol, to the exothermic effect of the salt solution. The entropy of solution affects the solubility of ammonium chloride in acetonitrile only slightly, in contrast to dioxane and 2-propanol in which the entropies of solution are significant and have opposite signs. The solubility of ammonium and potassium chlorides depends on the electron-acceptor power of the solvents and electrostatic interactions in solution, whereas the solubility of sodium chloride in organic solvents is determined by the combined influence of the donor-acceptor and dielectric properties of the solvents.

Empirical equations for the thermodynamic properties of aqueous sodium chloride

Equations for the thermodynamic properties of aqueous sodium chloride near its vapour pressure are presented. The equations are functions of temperature and concentration, and may be used to estimate aqueous sodium chloride's solubility, density, vapour pressure, specific enthalpy and entropy. They are valid for temperatures from 0 to 300°C, and concentrations extending to saturation with suitable accuracy. The thermodynamic equations are represented graphically and compared with published experimental data. These equations should prove to be a useful tool for modeling desalination equipment, particularly distillation processes.

Solubility of sodium chloride and sulfate in sub- and supercritical water vapor from 450–550°C and 100–250 bar

Abstract Armellini, F.J. and Tester,J.W., 1993. Solubility of sodium chloride and sulfate in sub- and supercritical water vapor from 450–550°C and 100–250 bar. Fluid Phase Equlibria, 84: 123-142. The solubility of sodium chloride in water vapor has been determined at supercritical temperatures ranging from 450–550°C and sub- and supercritical pressures varying from 100–250 bar. Measured sodium chloride concentrations ranged from 0.9–101 ppm (by weight). In the experiments, water vapor was saturated by continuously flowing it through a tube packed with solid salt. The results for sodium chloride agreed well with other studies which used continuous flow methods. Hydrolysis of the solid salt was found as a possible explanation for some of the reported discrepancies in the literature. Experiments with sodium sulfate at 500°C and 250 bar were also performed. Measured sodium sulfate concentrations were around 0.9 ppm, and exhibited unsteady behavior. Though only an estimate of Na2SO4 solubility could be obtained, this value was over two orders of magnitude lower than that for sodium chloride at identical conditions.

On the solubility of sodium chloride in water

In the present experiments the crystal growth rate of sodium chloride from aqueous solution has been studied. In particular, the solubility curve of NaCl/H 2O has been measured. Crystal growth and dissolution experiments were used to determine the saturation temperatures of the given solutions; the corresponding salt concentrations were measured by chemical analysis.

Solubility of sodium chloride in aqueous electrolyte solutions from 10 to 100 .degree.C

Solubility of sodium chloride in aqueous electrolyte solutions from 10 to 100 .degree.C

Solubility of sodium chloride in dry steam

Solubility of sodium chloride in dry steam

Solubility of sodium chloride and potassium chloride in aqueous hydrochloric acid from 20 to 85.degree.C

Solubility of sodium chloride and potassium chloride in aqueous hydrochloric acid from 20 to 85.degree.C

Solubility of sodium chloride in organic solvents with Aerosol OT in the presence of moisture

Measurements were made of the solubility of NaCl in perchlorethylene and in dodecane solutions of dioctyl sodium sulfosuccinate (Aerosol OT), in the presence of various amounts of water. Part of this water was found to be bonded to the detergent and not available for the solution of NaCl. The addition of water to an anhydrous solution of Aerosol OT produced a progressive ionization of the detergent. The micelles of the studied systems were all saturated with detergent, which explains the constancy of the sodium chloride solubility for the studied range of water content.

A DETERMINATION OF THE SURFACE FREE ENERGY OF SODIUM CHLORIDE

The surface free energy for the interface between crystalline sodium chloride and a saturated alcoholic solution was determined from the solubility of sodium chloride in absolute ethyl alcohol as a function of the particle size of the salt. At 298°K. a value of 171 ergs/cm.2 was found. A general discussion of the validity of the Ostwald equation, which relates solubility and particle size, is presented.