Density of Methanolic Alkali Halide Salt Solutions by Experiment and Molecular Simulation

Abstract

The density of methanolic alkali halide salt solutions is studied experimentally at 298.15 K, 308.15 K and 318.15 K at 1 bar for solutions containing all soluble combinations of alkali cations (Li + , Na + , K + , Rb + , Cs + ) with halide anions (F − , Cl − , Br − , I − ) at concentrations up to 0.05 mol/mol or 90% of the solubility limit. The density of the electrolyte solutions is also determined by molecular simulation in the same temperature and composition range. The used force fields of the ions were adjusted in previous works to properties of aqueous solutions and the solvent methanol to pure component properties. The force fields are of the Lennard-Jones (LJ) plus point charge type in case of the ions and of the LJ plus partial charges type in case of the solvent. For the present molecular simulations, no further adjustment of the force fields is carried out. The mixed interactions between the ions and methanol are predicted by the Lorentz− Berthelot combining rules. The predictions of the reduced density by molecular simulation are found to be in very good agreement with the experimental data. Furthermore, the radial distribution function of methanol around the ions, the solvation number and the residence time of methanol molecules in the first solvation shell, the self-diffusion coefficient of the ions, and the electric conductivity are systematically studied by molecular simulation and compared to experimental literature data where available.

On the properties of methanolic NaCl solution by molecular dynamics simulations

“…General trend of behaviour of D Cl and D Na is that they decrease in magnitude with augmenting molality in qualitative similarity to what was observed for aqueous solutions, see e.g., figure 14 of [44]. Our data in table 3 for VR-L2 differ but do not contradict the results for NaCl salt in methanol from the report of [57] at molality m ≈ 0.0313. The self-diffusion coefficient for Na + is lower than for Cl − according to the predictions of all models studied.…”

“…The simulation results for the entire set or models of this study are compared with experimental data from [66], in figure 1 (a). Slightly less comprehensive, experimental results concerning the density of the system in question at room temperature can be found also in [57,[67][68][69]. The experimental solubility limit has been established at m = 0.238, [70,71].…”

“…A set of models for liquid methanol, designed for application within the computer simulation methods, is quite ample [33,34,47,[50][51][52][53][54]. As concerns computer simulation studies of solutions of simple salts in methanol, we are aware of the following reports [55][56][57][58][59].…”

Solvent activity in electrolyte solutions from molecular simulation of the osmotic pressure

“…Simulation results using these models have shown good agreement with available experimental data for various properties such as liquid solution densities, radial distribution functions, diffusion coefficients and electric conductivities [14]. Furthermore, the model parameters are transferable so that methanolic and ethanolic electrolyte solutions can also be described [15,16].…”

Partial molar volume of NaCl and CsCl in mixtures of water and methanol by experiment and molecular simulation

“…Molecular dynamics (MD) simulations of methanol-water mixtures, employ-ing the Schnabel et al [30] model for methanol and several popular water models (including SPC/E) were previously conducted by Guevara-Carrión et al [33,34] and Paȓez et al [35], but with a focus on transport properties. In another previous study [36], the predictions obtained from combining the ion models of the set of Reiser et al [31] with the methanol model of…”