OPEN ACCESS
Journal of Multidisciplinary Applied Natural Science Vol.
5 No.
https://doi.
org/10.
47352/jmans.
Research Article The Nature of Processes Affecting the Solubility.
Viscosity, and Density Characteristics of Aqueous Electrolyte Systems Galiya Kambarova.
Ulzhalgas Nazarbek.
Saule Nazarbekova.
Perizat Abdurazova, and Yerkebulan Raiymbekov* Received : February 17, 2025 Revised : April 26, 2025 Accepted : May 11, 2025 Online : July 17, 2025 Abstract This study investigates the key factors influencing the solubility, viscosity, and density of aqueous electrolyte systems.
Model solutions of types 1-1, 1-2, 2-1, and 2-2 electrolytes were examined across a wide concentration range.
The results show that solubility increases with temperature due to a higher proportion of free water molecules, while greater electrolyte concentrations lead to a rise in viscosity and density.
It was found that ion radius and charge density strongly impact solution properties: larger ion radii and lower charge densities decrease viscosity and increase density, whereas smaller radii and higher charge densities have the opposite effect.
The findings offer new insights into the relationship between ionic parameters and macroscopic solution behavior, supported by mathematical modeling and graphical analysis.
Keywords solubility, viscosity, density, aqueous electrolyte systems, hydrated ions INTRODUCTION Currently, the theory of the liquid state of substances, including aqueous electrolyte solutions, is still in its early stages of development.
To date, a significant amount of experimental and factual data has been accumulated regarding the diverse physicochemical properties of aqueous electrolyte solutions .
However, much of this highly reliable information has yet to receive a comprehensive scientific explanation.
In this area of scientific inquiry, despite some relative progress in the theory of dilute solutions, no significant advancements have been made thus far .
Aqueous solutions play a significant role in engineering and technology.
Currently, there is a wide variety of chemical-technological processes, most of which are carried out in liquid-phase aqueous-electrolyte The technological regimes and parameters of any processes occurring in aqueous-electrolyte systems are determined based on their PublisherAos Note:
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A 2025 by the author.
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Metro.
Indonesia.
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0/).
concentration, density, viscosity, and various thermal properties.
The current level of knowledge in the theory and practice of inorganic chemical technology indicates that the causal nature of changes in the viscosity and density of aqueous electrolyte solutions is still not fully understood.
Additionally, there is a lack of clarity regarding the processes and phenomena underlying the hydration of ions in water.
The existing literature primarily provides qualitative explanations from the perspectives of intermolecular interaction forces, the principles of chemical kinetics, hydrostatics, hydraulics, and similar fields .
Therefore, the development of new scientific principles concerning the nature and mechanisms of changes in the key physicochemical properties of aqueous electrolyte solutions, as well as establishing the dependence of ion hydration numbers on their specific charge density, represents a critical task.
Studies on the viscosity and density of aqueous electrolyte solutions cover a wide range of compounds, including salts of alkali and transition metals, acids, and mixed systems .
For example, the investigation of ternary solutions of CaClCC and KCl in the temperature range of 293Ae323 K revealed that the solution's viscosity exceeds that of water by 15% at low concentrations and increases up to 270% at high concentrations, with CaClCC having a more pronounced effect on viscosity compared to KCl .
Similar patterns have been established for aqueous and water-ethanol solutions of MgSOCE, where an increase in electrolyte concentration leads to a rise in viscosity, while an J.
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Table 1.
Radius and surface charge density of ions.
Metal ions Ion radius () Surface ion charge density (C/.
Co 2 increase in temperature causes its reduction.
These studies confirm the structure-forming role of MgAA in aqueous solutions, as manifested in the enhancement of ion-ion interactions with increasing temperature .
The analysis of the density of aqueous electrolyte solutions is also a crucial research In particular, recently obtained experimental data for pure and mixed solutions of NaCl and CaClCC in the temperature range of 293Ae 353 K allowed for the refinement of existing numerical models for the density of geothermal fluids .
This confirms the significance of such studies for accurately predicting density parameters at high temperatures and pressures.
However, previous studies have mainly focused on the effects of concentration and temperature on the macroscopic properties of specific electrolyte systems, without systematically analyzing the influence of intrinsic ion parameters, such as ionic radius and charge density.
In contrast, the present study provides a comprehensive investigation into how the radius and charge density of hydrated ions affect the solubility, viscosity, and density of various aqueous electrolyte solutions.
This integrated approach enables a deeper understanding of the structural and physicochemical behavior of electrolyte solutions across a wide range of concentrations and temperatures.
The structural characteristics of aqueous electrolyte solutions are largely determined by their ionic composition, concentration, and temperature Studies of colloidal systems have shown that surface charge and hydration are key factors influencing the stability of aqueous suspensions.
has been established that monovalent and divalent ions exert different effects on adsorption and hydration .
High electrolyte concentrations lead to enhanced long-range ionic correlations, which significantly impact the structure of interfacial Furthermore, an important research direction is the ionic conductivity of solutions.
In the case of acidic solutions such as HCl.
HNOCE.
HCCSOCE, and HCEPOCE, it has been established that conductivity depends not only on concentration but also on the characteristics of the phase diagram of the system.
The analysis of ion transport in such solutions has identified two dominant mechanismsAi"hopping" and "vehicular", which play a key role in charge J.
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Table 2.
Parameters of the studied water-electrolyte mixtures.
Water-electrolyte Range of changes in solution concentrations, mol % H2O Ae LiCl 05:14.
H2O Ae NaCl 03:9.
H2O Ae KCl 03:6.
H2O Ae CsCl 01:13.
H2O Ae LiI 01:14.
H2O Ae NaI 01:15.
H2O Ae KI 01:11.
H2O Ae CsI 01:4.
H2O Ae Li2SO4 02:3.
H2O Ae Na2SO4 01:2.
H2O Ae K2SO4 01:2.
H2O Ae Co(NO.
2 01:7.
H2O Ae Ni(NO.
2 01:6.
H2O Ae Mg(NO.
2 01:7.
H2O Ae Mn(NO.
2 01:6.
H2O Ae Zn(NO.
2 01:5.
H2O Ae Cd(NO.
2 01:0.
H2O Ae Cu(NO.
2 01:8.
H2O Ae Ca(NO.
2 01:9.
H2O - Sr(NO.
2 01:5.
H2O Ae Pb(NO.
2 01:2.
H2O Ae CoCl2 01:2.
H2O Ae NiCl2 01:5.
H2O Ae MgCl2 02:8.
H2O Ae MnCl2 01:8.
H2O Ae FeCl2 01:5.
H2O Ae ZnCl2 01:23.
H2O Ae CdCl2 01:7.
H2O Ae CaCl2 02:3.
H2O Ae SrCl2 01:14.
H2O Ae BaCl2 01:2.
H2O Ae CoSO4 01:4.
H2O Ae NiSO4 01:3.
H2O Ae MgSO4 02:3.
H2O Ae MnSO4 01:6.
H2O Ae FeSO4 01:2.
H2O Ae ZnSO4 01:5.
H2O Ae CdSO4 01:4.
H2O Ae CuSO4 01:2.
Temperature of solutions.
A J.
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transfer across different concentration ranges .
Additionally, electrolytes are widely used in electrochemical systems, such as ChCl:AA (Choline ChlorideAeAcetic Aci.
solutions, which exhibit promising properties as background electrolytes in electrochemical studies .
Experimental data on viscosity, electrical conductivity, and electrochemical window width confirm their suitability for use in electrochemical redox systems, making them promising for further Studies of aqueous electrolyte systems cover a wide range of aspectsAifrom macroscopic properties such as density and viscosity to molecular mechanisms of hydration and ion transport .
The obtained data hold both fundamental and applied significance, finding electrochemistry, and materials science.
The aim of this study is to investigate the processes affecting the solubility, viscosity, and density of aqueous electrolyte systems and to identify the patterns of their changes depending on concentration, temperature, and the parameters of ionic The scientific novelty of this research lies in the fact that, for the first time, a comprehensive analysis of the influence of ion radius and charge density on the macroscopic parameters of aqueous electrolyte solutions .
iscosity, density, and solubilit.
has been The study experimentally confirms a quantitative relationship between the radius of the hydrated ion, its charge density, and the structure of the aqueous electrolyte medium, which has not been previously examined in such a comprehensive Figure 1.
Temperature dependence of chloride Figure 2.
Temperature dependence of iodide MATERIALS AND METHODS The research was conducted on model aqueous solutions of electrolytes of types 1-1, 1-2, 2-1, and The model solutions were prepared using reagent-grade samples of LiCl.
NaCl.
KCl.
CsCl.
LiI.
NaI.
KI.
CsI.
LiCCSOCE.
NaCCSOCE.
KCCSOCE.
Co(NOCE) CC.
Ni(NOCE)CC.
Mg(NOCE)CC.
Mn(NOCE)CC.
Zn(NOCE)CC.
Cd (NOCE)CC.
Cu(NOCE)CC.
Ca(NOCE)CC.
Sr(NOCE)CC.
Pb(NOCE)CC.
CoClCC.
NiClCC.
MgClCC.
MnClCC.
FeClCC.
ZnClCC.
CdClCC.
CaClCC.
SrClCC.
BaClCC.
CoSOCE.
NiSOCE.
MgSOCE.
MnSOCE.
FeSOCE.
ZnSOCE.
CdSOCE.
CuSOCE (Ou99.
, and distilled water obtained using an AQUA-DISTILLER DE-4-2 over a wide concentration range.
The salts were dried at 105 AC for 2 h prior to use to remove surface moisture.
Solutions were prepared gravimetrically by weighing the appropriate amounts of solid using an analytical balance .
ccuracy A0.
and diluting to the required volume using calibrated volumetric flasks .
lass A, tolerance A0.
05 mL for 100 mL flask.
Concentrations were calculated based on the mass of solute and the final volume of the solution.
The uncertainty in concentration was estimated to be less than A0.
The physicochemical properties of the investigated aqueous-electrolyte mixtures were determined using standard analytical methods and modern control instruments.
The obtained results were subjected to comparative analysis with publicly available reference data.
Graphical and J.
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Figure 3.
Temperature dependence of nitrate Figure 4.
Temperature dependence of the solubility of potassium and rubidium nitrates.
Figure 5.
Temperature dependence of sulfate solubility.
mathematical methods were employed to analyze and summarize the literature data and experimental findings regarding the influence of ion radius, ion charge density, and solution concentration on the changes in viscosity and density of the studied solutions .
I .
is used as a unit of length, where 1 yI = 0.
1 n.
When necessary, experiments were conducted under thermostatic conditions using a liquid laboratory thermostat, model SJML-19/2.
5I1.
The research was conducted taking into account the most reliable data on the radius and charge density of ionic components in binary and ternary electrolyte solutions of types 1-1, 1-2, 2-1, and 2-2 (Table .
over a wide concentration range at a constant temperature (Table .
Determination of Solution Density using a Pycnometer Equipments used were analytical balance, weight set, pycnometer, vessel containing the test liquid, vessel with distilled water, vessel with water at room temperature, thermometer, and filter paper.
The density of solutions was determined using a calibrated pycnometer .
000 A 0.
002 mL) at a controlled temperature of 20.
0 A 0.
1 AC.
The pycnometer was calibrated using distilled water prior to each series of measurements.
A pycnometer is a vessel of a precisely defined and constant By sequentially filling it with the test solution and distilled water and weighing, the density of the solution can be determined using the following expression 1.
P is the mass of the pycnometer with the solution .
Q is the mass of the pycnometer with water .
, p is the mass of the pycnometer .
, and is the density of water at a given temperature .
/ Determination of Solution Viscosity using a V3Type Viscometer The V3-type viscometer is a falling ball viscometer compliant with TGL 29 202/03 and DIN 53 015 standards.
The viscometer measures the time J.
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Figure 6.
Dependence of solution viscosity on concentration at constant temperature of 20 AC.
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it takes for a ball to fall through a cylindrical tube filled with the test liquid, inclined at 10A from the The V3-type viscometer is primarily designed for measuring the viscosity of Newtonian The viscometer was calibrated using standard viscosity fluids and distilled water .
ynamic viscosity of water at 20 AC: 1.
002 mPaA.
All measurements were performed in triplicate to ensure reproducibility.
Measured Quantity:
Dynamic viscosity, expressed in PaAs or mPaAs.
The dynamic viscosity is calculated using the following quadratic function 4.
where a2,b2,c2 are polynomial regression coefficients determined for each .
The approximation of solubility, viscosity, and density dependencies was conducted using the multiple nonlinear regression method based on experimental data.
The least squares method (LSM) was applied to minimize fitting errors.
The regression analysis was performed using Microsoft Excel .
uilt-in LINEST and trendline fitting tool.
For each fitted equation, the coefficient of determination (RA) was calculated to evaluate the goodness of fit.
Where applicable, 95% confidence intervals for the regression coefficients were also Polynomial models were employed to achieve an accurate empirical description of viscosity and density behavior over a broad concentration range, especially where classical models like the JonesAeDole equation are less However, it is acknowledged that such models are valid strictly within the studied concentration and temperature limits and lack a fundamental theoretical basis for extrapolation beyond these conditions.
where: = dynamic viscosity in millipascal seconds .
PaA.
, q1 = density of the ball .
/cm.
, q2 = density of the liquid at the operating temperature .
/cm.
E = time of ball fall .
, and K = ball constant .
PaAcm3/.
Both q1 and K are given for each ball in the test certificate.
The expression in brackets .
1 Ae q.
is a correction for the buoyancy force acting on the ball in the solution.
To describe the physicochemical properties of approximations of different orders were employed based on the behavior of the experimental data.
The dependencies of solubility (M.
, viscosity (), and density (A) on temperature (T) and concentration (C) were modeled using quadratic equations, as these properties exhibited smooth, monotonic trends without inflection points across the studied ranges.
In contrast, to characterize the relationships between viscosity and microscopic ionic parameters, such as ionic radius and charge density, cubic polynomial models were utilized to capture more complex, nonlinear behaviors observed in the experimental results.
Solubility (M.
of electrolytes in water, expressed in molar percentage, is approximated by a quadratic function of temperature .
where a1, b1, c1 are empirical coefficients determined for each .
Viscosity () of solutions at a constant temperature depends on the concentration of the dissolved substance and is also described by a .
Density (A) of aqueous electrolyte solutions is similarly described by a concentration-dependent where a3,b3,c3 are empirical parameters defined for specific salts.
RESULTS AND DISCUSSIONS
Solubility of Electrolytes The results of the graphical analysis of data on the solubility changes of the studied aqueous-salt systems with temperature are shown in Figures 1 Ae From the results, it is evident that the solubility of the examined aqueous-electrolyte mixtures consistently increases with rising temperature.
This observed pattern remains consistent throughout the entire studied temperature range of the solutions.
Recent studies using molecular dynamics and field-theoretical modeling have demonstrated that while ions affect the dielectric properties and J.
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Figure 7.
Dependence of the viscosity of solutions on the ion radius at constant concentration and temperature .
AC) J.
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induce screening in aqueous solutions, the hydrogen -bonded network of bulk water remains largely intact away from the hydration shells .
This distinction between localized structured water and bulk-like free water supports the assumption that increasing temperature enhances the proportion of free water molecules, facilitating the solubility of This is confirmed by the polynomial dependencies obtained for the molar solubility of salts such as NHCECl.
KCl.
BaClCC.
CoClCC.
NiClCC.
SrClCC.
MgClCC.
CsCl, and LiCl, presented as follows:
theoretically lead to a reduction in the total number of free water molecules and, consequently, a slowdown in the dissolution process.
However, with increasing temperature, the bound portion of bulk water, which does not effectively interact with the electrolyte molecules and does not decrease in number, undergoes thermal destruction.
This thermal breakdown results in the formation of new free water molecules in the solution, which are capable of further enhancing the solubility of electrolytes as the temperature increases .
us NH4Cl = 0.
00007T2 0.
108T 9.
us KCl = -0.
0001T2 0.
0666T 6.
us BaCl2 = 0.
00003T2 0.
018T 2.
us CoCl2 = -0.
0004T2 0.
1178T 5.
us NiCl2 = -0.
0003T2 0.
0711T 6.
us SrCl2 = -0.
0001T2 0.
0685T 4.
us MgCl2 = 0.
0002T2 0.
0080T 9.
Viscosity Characteristics of Aqueous Electrolyte Mixtures The potential diversity of properties in any solution depends on the physicochemical characteristics of its individual componentsAithe dissolved substances and solventsAias well as on the properties of newly formed structural elements and their assemblies derived from the original substances in the solution.
In aqueous electrolyte systems, the primary constituents are various types of positively and negatively charged ions.
According to modern concepts of solution structure, these ions are surrounded by hydration shells formed from solvent water molecules, which can be categorized into two distinct types: bound water and free water .
Bound water refers to molecules directly coordinated to the ions, forming the first hydration shell with restricted mobility and altered hydrogen bonding.
In contrast, free water denotes the bulk-like molecules not directly involved in ion coordination and retaining their dynamic properties.
The ions in solution therefore exist as hydrated complexesAistructural units whose behavior depends strongly on their charge density and radius.
To date, all aspects of the critical question regarding the influence of the structural components of solutions on their characteristic physicochemical properties remain unresolved, lacking exhaustive and scientifically grounded explanations.
Existing insights and the associated hypotheses often lack irrefutable quantitative validation and are predominantly of a contentious nature .
analysis of the current level of knowledge in the theory and practice of inorganic chemical technology indicates that the causal relationships governing the impact of external factors on the As can be seen, the group of dependencies is identical to expression 6, and differ from the latter only in the order of constants preceding the temperature factor, which should be understood as a reflection of the physicochemical properties of the salt components in the solution.
N = -0.
0634T2 2.
7475T 16.
The bound fraction of water molecules does not exert a significant influence on the solubility of electrolytes, as these molecules exist as large and hydrophobic complexes.
A key distinction between these insights and the currently accepted concepts of electrolyte solubility in water lies in the fact that, for the first time in scientific practice, these findings are based on the actual identical temperature dependence of the solubility of aqueous -salt mixtures and the quantitative composition of free water molecules in the solvent.
Thus, a system should be conceptualized as a mixture of aqueoussalt complexes composed of the ionic components of the salt, the free fraction of water molecules, the residual fraction of water molecules, and hydrophobic water formations that do not participate in any significant medium-altering interaction with the electrolyte molecules.
As the temperature rises, the concentration of aqueous-ionic complexes increases, which should J.
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Figure 8.
Dependence of solution viscosity on the ion charge density at constant concentration and temperature of 20 AC J.
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changes in viscosity, density, heat capacity, and thermal conductivity of aqueous-electrolyte solutions have yet to be adequately and comprehensively elucidated.
Existing literature on this subject largely provides only qualitative explanations based on intermolecular interaction forces, the principles of chemical kinetics, hydrostatics, and hydraulics.
In our view, these explanations fall short of thoroughly and In this regard, the objectives of this part of the study were focused on developing new scientific principles regarding the nature and behavior of viscosity changes in aqueous electrolyte solutions as a function of temperature and concentration and formulating a fundamentally new approach to explaining these phenomena .
The targeted research was based on contemporary concepts of the structure of water and aqueous systems, as well as the key principles and conclusions established to date regarding the structure and properties of aqueous-electrolyte mixtures.
The results of the graphical analysis of viscosity parameters for the studied aqueous-electrolyte mixtures of types 1-1, 1-2, 2-1, and 2-2, exemplified by the systems HCCOAeLiCl.
HCCOAeNaCl.
HCCOAeKCl.
HCCOAeCsCl.
HCCOAeLiCCSOCE.
HCCOAeNaCCSOCE.
HCCOAeKCCSOCE.
HCCOAeCoClCC.
HCCOAeNiClCC.
HCCOAeMgClCC.
HCCOAeMnClCC.
HCCOAeFeClCC.
HCCOAeZnClCC.
HCCOAeMnSOCE.
HCCOAeZnSOCE.
HCCOAeCdSOCE.
HCCOAeCuSOCE.
HCCOAeLiI.
HCCOAeNaI.
HCCOAeKI.
HCCOAeCsI.
HCCOAeMg(NOCE)CC.
HCCO AePb(NOCE)CC.
HCCOAeCd(NOCE)CC.
HCCOAeSr(NOCE)CC.
HCCOAe Mn(NOCE)CC.
HCCOAeFeSOCE, and HCCOAeMgSOCE at constant temperature of 20 AC are shown in Figures 6 Ae 8.
The examined aqueous-salt systems at contant temperature of 40 AC exhibit similar dependencies.
Figures 7 and 8 illustrate the behavior of viscosity changes in various electrolyte solutions differing in concentrations within each individual type.
The group of experimental points labeled as "1" in Figures 7.
corresponds to the radii and surface charge densities of ions listed in Table 1.
The data in Figures 6Ae8 show that: the viscosity of mixtures at constant temperature increases with increasing concentration and can be described by polynomial dependencies of the following types:
LiCl = 0.
NaCl = 0.
KCl = 0.
0012 Ae 0.
CsCl = 0.
0022 Ae 0.
The viscosity characteristics of solutions with other types of salts exhibit similar dependencies.
For all the studied types of aqueous-electrolyte mixtures, it is observed that when the dissolved salts contain identical anions, at the same solution concentration, the smaller the cation radius, the higher the viscosity of the solution (Figures 6.
Ae .
The viscosity characteristics of aqueouselectrolyte systems at constant temperature are influenced by the ion radius.
It has been established that there is a specific mathematical relationship between the viscosity of solutions and the ion radius, described by the following types of For solutions of LiCl.
NaCl.
KCl, and CsCl = 0.
127r3 Ae 0.
= 0.
123r3 Ae 0.
185r2 Ae 0.
= 0.
172r3 Ae 0.
195r2 Ae 0.
= 0.
328r Ae 0.
620r Ae 0.
= 0.
806r3 Ae 2.
= 1.
367r Ae 4.
= 2.
168r3 Ae 6.
= 2.
841r Ae 8.
For solutions of Li2SO4.
Na2SO4, and K2SO4 = -0.
= -0.
= -0.
= -0.
The viscosity characteristics of solutions with other types of salts exhibit similar dependencies.
For all types of the studied aqueous-electrolyte mixtures, it is evident that as the ion radius .
n this case, cation radiu.
increases, in all cases where the concentration of the aqueous-electrolyte mixtures is constant and the same anionic components are present, the viscosity of the solutions decreases (Figures 7.
Ae.
As shown in Figures 8.
Ae.
, the viscosity characteristics of solutions, in cases with identical anionic components and the same solution concentration, are also influenced by the charge density of the cations.
It has been J.
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Figure 9.
Dependence of solution density on concentration at constant temperature .
AC) J.
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established that there is a specific mathematical relationship between the viscosity of aqueouselectrolyte systems and the charge density of the cations, described by the following types of For solutions of LiCl.
NaCl.
KCl, and CsCl = -35.
02PA3 11.
11PA2 Ae 0.
154PA 0.
= -50.
12PA3 14.
92PA2 0.
543PA 0.
= -93.
45PA3 30.
42PA2 Ae 0.
240PA 0.
= -140.
4PA3 46.
16PA2 Ae 0.
855PA 0.
= -249.
1PA3 84.
55PA2 Ae 3.
815PA 0.
= -397.
9PA3 139.
2PA2 Ae 8.
718PA 1.
= -567.
2PA3 199.
6PA2 - 13.
88PA 1.
= -767.
2PA3 274.
7PA2 Ae 21.
04PA 1.
For solutions of MnSO4.
ZnSO4.
CdSO4, and CuSO4 = 178.
9PA2 Ae 110.
8PA 22.
= 102.
9PA2 Ae 64.
32PA 14.
= 3.
129PA Ae 1.
346PA 3.
= 10.
89PA Ae 6.
609PA 4.
= -3.
782PA2 3.
334PA 1.
= 0.
841PA 0.
004PA 1.
= -0.
795PA 0.
921PA 1.
= -4.
918PA2 3.
783PA 0.
= -0.
818PA 0.
769PA 1.
The viscosity behavior of all studied systems exhibits a consistent pattern: viscosity increases with higher electrolyte concentration and with increasing charge density of the cations.
At constant temperature, this rise in viscosity is attributed to the greater number of hydrated ions in the solution, which enhances molecular interactions and resistance to flow.
Additionally, variations in the ionic radius and charge density significantly influence the viscosity.
Smaller ionic radii and higher charge densities promote stronger coordination with water molecules, leading to the formation of larger hydrated complexes and a corresponding increase in solution viscosity (Figures 6Ae.
These findings confirm that aqueouselectrolyte mixtures behave as molecular-kinetic systems composed of hydrated ions .
queouselectrolyte complexe.
whose structural and dynamic properties are primarily governed by the concentration, ionic radius, and charge density of the dissolved species .
Density Characteristics of Aqueous-Electrolyte Mixtures The objectives of this part of the study were to develop new scientific principles regarding the nature and behavior of density changes in aqueous electrolyte solutions as a function of temperature and concentration and to formulate a fundamentally new approach to explaining these phenomena.
The results of the graphical analysis of the density characteristics of the studied binary and ternary aqueous-electrolyte mixtures of types 1-1, 1-2, 2-1, and 2-2, exemplified by the systems HCCOAeLiCl.
HCCOAeNaCl.
HCCOAeKCl.
HCCOAeCsCl.
HCCOAeLiCCSOCE.
HCCOAeNaCCSOCE.
HCCOAeKCCSOCE.
HCCOAeCoClCC.
HCCOAe NiClCC.
HCCOAeMgClCC.
HCCOAeMnClCC.
HCCOAeFeClCC.
HCCOAe ZnClCC.
HCCOAeMnSOCE.
HCCOAeZnSOCE.
HCCOAeCdSOCE.
HCCOAeCuSOCE.
HCCOAeLiI.
HCCOAeNaI.
HCCOAeKI.
HCCOAe CsI.
HCCOAeMg(NOCE)CC.
HCCOAePb(NOCE)CC.
HCCOAeCd (NOCE)CC.
HCCOAeSr(NOCE)CC.
HCCOAeMn(NOCE)CC.
HCCOAe FeSOCE, and HCCOAeMgSOCE at constant temperature .
AC) are shown in Figures 9, 10, and 11.
The studied aqueous-salt systems at constant temperature .
AC) exhibit similar dependencies.
The data in Figures 9Ae11 show that the density of mixtures at constant temperature increases with increasing concentration and can be described by polynomial dependencies of the following types:
A CsI = -7.
A KI = -1.
A NaI = -1.
A LiI = -1.
The density characteristics of solutions with other types of salts exhibit similar dependencies.
For all studied types of aqueous-electrolyte mixtures, it is observed that when the dissolved salts contain identical anions, at the same solution concentration, the smaller the cation radius, the lower the solution density (Figures 9 .
Ae.
The density characteristics of solutions at constant temperature are influenced by the ion radius.
It has been established that there is a specific mathematical relationship between the density of aqueous-electrolyte systems and the ion radius, described by the following types of dependencies:
For solutions of CsI.
KI.
NaI, and LiI A = 925.
1r3 - 3008r2 3249r 109.
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Figure 10.
Dependence of solution density on the ion radius at constant concentration and temperature .
AC) J.
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A = 889.
0r3 - 2899r2 3139r 120.
A = 829.
6r3 - 2704r2 2923r 173.
A = 779.
8r3 - 2549r2 2762r 201.
A = 714.
4r3 - 2350r2 2559r 242.
A = 584.
7r3 - 1931r2 2115r 366.
A = 461.
3r3 - 1528r2 1678r 491.
A = 329.
3r3 - 1098r2 1214r 624.
For solutions of Li2SO4.
Na2SO4, and K2SO4 A = -293.
A = -225.
A = -156.
A = -79.
0r 920 .
The density characteristics of solutions with other types of salts exhibit similar dependencies.
For all studied types of aqueous-electrolyte mixtures, it is observed that as the ion radius .
n this case, cation radiu.
increases, in all cases where the concentration of the aqueous-electrolyte mixtures is constant and identical anionic components are present, the solution density increases (Figures 10 .
Ae.
As shown in Figures 11 .
Ae.
, the density characteristics of systems, in cases with identical anionic components and the same solution concentration, are also influenced by the charge density of the cations.
It has been established that there is a specific mathematical relationship between the density of aqueous-electrolyte systems and the charge density of the cations, described by the following types of dependencies:
For solutions of CsI.
KI.
NaI, and LiI A = -38788PA3 38640PA2 Ae 12607PA 2533.
A = -36463PA3 35735PA2 Ae 11335PA 2314.
A = -28431PA3 27905PA2 Ae 8867PA 2027 .
A = -19950PA3 19601PA2 Ae 6232PA 1718 .
A = -10294PA3 10115PA2 Ae 3216PA 1369 .
For solutions of Li2SO4.
Na2SO4, and K2SO4 A = -2170PA2 222.
3PA 1138
A = -1762PA2 212.
8PA 1100
A = -1258PA 163.
9PA 1066
A = -634.
8PA 80.
66PA 1033
cations increases, the solution density decreases.
is evident that the key factors influencing the changes in the density characteristics of aqueoussalt systems are the concentration of dissolved substances, the radius, and the charge of the ionic components .
In all cases, at constant temperature, the increase in solution density should be understood as a result of the quantitative increase in hydrated ions within the solution volume as concentration rises.
The behavior of density changes in the studied solutions at the same solution concentration, depending on the radius and charge density of the ions, indicates that the smaller the radius and the higher the charge density of the ion, the greater the degree of coordination of the ions with water molecules.
As a result, the geometric dimensions of the hydrated ions increase, leading to the growth of free voids in the solution, which in turn decreases the solution density (Figures 9.
Ae .
The observations in Figures 10.
Ae.
Ae.
, obtained under conditions where several solutions differ in concentration, but each individual solution maintains a concentration, demonstrate that the geometric dimensions of hydrated ions also change depending on their radius and charge density .
This is reflected in the corresponding patterns of density Based on the aforementioned results and the analysis of the behavior of density changes in the studied aqueous-electrolyte mixtures, it can also be concluded that the aqueous-electrolyte medium represents a molecular-kinetic system where the primary medium-forming role is assigned to hydrated ions, also known as aqueous-electrolyte complexes with a specific and finite degree of The parameters and characteristics of hydrated ions are significantly influenced by the concentration, radius, and charge density of the ionic components in the solution.
These factors, in turn, have a consequential impact on the behavior of all physicochemical properties of the solution, including its density.
CONCLUSIONS
The density characteristics of solutions with other types of salts exhibit similar dependencies.
For all studied types of aqueous-electrolyte mixtures, it is observed that as the charge density of The solubility of electrolytes in water is primarily influenced by the free component of bulk An increase in its quantity in the aqueous J.
Multidiscip.
Appl.
Nat.
Sci.
Figure 11.
Dependence of solution density on the ion charge density at constant concentration and temperature .
AC) J.
Multidiscip.
Appl.
Nat.
Sci.
medium with rising temperature promotes higher solubility of electrolytes.
The higher the concentration of dissolved electrolytes in water, the greater the number of hydrated ions in the solution.
Consequently, as the concentration of electrolyte solutions increases, their viscosity and density also Under constant concentration and temperature conditions, the viscosity and density of electrolyte solutions are determined by the radius and charge density of the ionic components in the For all types of aqueous-electrolyte mixtures at constant concentration and temperature, an increase in the radius of the ionic components and a corresponding decrease in their charge density lead to a reduction in viscosity and an increase in solution density.
Conversely, a decrease in the radius of hydrated ions and a corresponding increase in their charge density result in the opposite effectAian increase in viscosity and a decrease in solution density.
(Kazakhsta.
org/0000-0003-2126-944X Perizat Abdurazova Ai Department of Chemistry.
Zhanibekov University.
Shymkent160012 (Kazakhsta.
org/0000-0002-5244-7678 Author Contributions Conceptualization.
Methodology, and WritingAiOriginal Draft Preparation.
Software.
Formal Analysis, and Visualization.
Validation.
Investigation.
Resources.
Data Curation.
WritingAiReview Editing.
Supervision.
Project Administration, and Funding Acquisition.
All authors have read and agreed to the published version of the manuscript.
Conflicts of Interest The authors declare no conflict of interest.
AUTHOR INFORMATION
ACKNOWLEDGEMENT
Corresponding Author Yerkebulan Raiymbekov Ai Research Lab of Besterekov AuWater Quality Monitoring and Water TechnologiesAy.
Auezov South Kazakhstan University.
Shymkent-160012 (Kazakhsta.
org/0000-0002-2119-2406 Email: eplusr@bk.
This research was funded by the Ministry of Higher Education and Science of the Republic of Kazakhstan, grant number a23487663.
Authors Galiya Kambarova Ai Research Lab of Besterekov AuWater Quality Monitoring and Water TechnologiesAy.
Auezov South Kazakhstan University.
Shymkent-160012 (Kazakhsta.
org/0000-0002-8417-3384 Ulzhalgas Nazarbek Ai Research Lab of Besterekov AuWater Quality Monitoring and Water TechnologiesAy.
Auezov South Kazakhstan University.
Shymkent-160012 (Kazakhsta.
org/0000-0001-8890-8926 Saule Nazarbekova Ai Research Lab of Besterekov AuWater Quality Monitoring and Water TechnologiesAy.
Auezov South Kazakhstan University.
Shymkent-160012
REFERENCES