KBr Solutions Research Articles

Volumetric Studies of 2,2,2-Cryptand in Aqueous and Aqueous KBr Solutions at 298.15 K: An Example Involving Solvent-Induced Hydrophilic and Hydrophobic Interactions

Density measurements of good precision are reported for aqueous and aqueous salt (KBr) solutions containing 2,2,2-cryptand (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane) (~0.009 to ~0.24 mol·kg−1) for the binary systems and for the ternary system with ~0.1 mol·kg−1 2,2,2-cryptand and varying KBr concentrations (~0.06 to ~ 0.16 mol·kg−1) at 298.15 K. The density data have been used to study the variation of apparent molar volume (\( \varphi_{V} \)) of 2,2,2-cryptand and of KBr as a function of concentration. 2,2,2-Cryptand is a diamine and hence it is hydrolyzed in aqueous solutions and needs an appropriate methodology to obtain meaningful thermodynamic properties. We have adopted a method of hydrolysis correction developed initially by Cabani et al. and later by Kaulgud et al. to analyze our volumetric data for the aqueous solutions. The method is described and we were successful in obtaining the limiting partial molar volume of the bare (free) cryptand in water at 298.15 K. Volumes of ionization as well as volumes of complexation (with KBr) are calculated. Estimations of the apparent molar volume of 2,2,2-cryptand in CCl4 are also reported. There is a loss in volume for the cryptand on transferring it from CCl4 to water. The volume changes due to ionization for the cryptand in water are calculated to be –20.5 and –0.6 cm3·mol−1 for the mono- and di-protonation equilibria respectively, while the volume of complexation for K+ is +24.5 cm3·mol−1. The results are discussed in terms of conformation, protonation equilibria and selective encapsulation of K+ ions in cryptand cavities. The solution volume properties seem to depend upon water–solute interaction as well on the solute–solute association because of hydrophobic interactions caused by lowering of the charge density on formation of cryptand-K+ species in solution.

Remarkable effect of bromide ion upon two-dimensional faradaic phase transition of dibenzyl viologen on an HOPG electrode surface: Emergence of two-step transition

We found that dibenzyl viologen (dBV) on an HOPG electrode undergoes a two-step first order faradaic phase transition at high concentrations of bromide ion (Br−). Results of voltammetric and electroreflectance measurements were used to describe the mechanism of the two-step transition processes. When [Br−]>180mM, the transition step at less negative potential was ascribed to a phase transition between a gas-like adsorption layer of dBV dication (dBV2+) and a mesophase of dBV radical cation (dBV+). Most likely, the mesophase is a two-dimensional (2D) ordered phase composed of co-adsorbed dBV+ and Br− where both are in direct contact with the HOPG surface. The transition step at more negative potential was ascribed to a phase transition between the dBV+ Br− mesophase and a 2D condensed phase of dBV+. In the condensed phase being denser than the mesophase, dBV+ molecules are π-stacked due to face-to-face interaction between bipyridinium radical cations. This transition step involves also a reduction process of dBV2+ to dBV+ followed by its incorporation into the condensed phase. The two-step transition was not observed in KCl solution of any concentration, either in KBr solution of [Br−]<75mM. Other viologens examined, including benzyl–heptyl viologen, did not exhibit such a two-step transition but single-step one. The nature of the transition, especially in the [Br−] range from 75 to 180mM, was closely analyzed.

Optimization of Activated Carbon Sulfurization to Reach Adsorbent with the Highest Capacity for Mercury Adsorption

This work deals with the use of elemental sulfur immobilized on the activated carbon surface, as an active phase to enhance the sorbent's mercury adsorption capacity. The sulfurization procedure was optimized, and the influence of two factors (temperature and initial ratio of sulfur to carbon), on the final properties and mercury adsorption capacities of the adsorbents was investigated. The sulfurized adsorbents were characterized using CHNS/O elemental analysis, surface area and porosimetry, FT-IR spectroscopy, SEM-EDS, and pHpzc measurement. A series of batch studies were also conducted to delineate the effect of contact time, initial pH, solution temperature, and initial mercury concentration on the adsorption capacity of the adsorbents. Furthermore, attempts were made to desorb mercury from the metal loaded adsorbents using various concentrations of KCl, KBr and KI solutions.

Light absorption in solutions of cetyltrimethylammonium and cetylpyridinium bromides

Absorption of monochromatic light in solutions of cetyltrimethylammonium (CTAB) and cetylpyridinium (CPB) bromides has been studied in the wavelength λrange of 190–1000 nm. The investigation has been performed at 30°C and surfactant concentrations ranging from 5 × 10−5 to 3.5 × 10−3 M. Spectra of solutions of LiBr, KBr, and CTAB in the premicellar concentration region have been shown to coincide with each other. They are unimodal, and the heights of their maxima at λmax ≈ 193 nm depend on Br− concentration alone. In contrast to CTAB solutions, the UV spectra of CPB solutions are characterized by the presence of two absorption maxima near λmax1 = 191 nm and λmax2 = 259 nm, as well as a shoulder at 210–218 nm. Their existence is caused by the presence of both Br− anions and CP+ cations in the solutions. The dependences of the integral absorption in the examined wavelength range on CPB concentration exhibit inflections both in the premicellar region and upon the transition to micellar solutions, with these inflections characterizing the critical dimerization and micellization concentrations, respectively. For CTAB, this regularity has only been observed at the critical micellization concentration. The data on the concentration dependence of the light absorption have resulted in the proposal of a method for determining the degree β of counterion binding by micelles of ionic surfactants. The β values calculated for CTAB and CPB are equal to 0.89 ±0 0.1.

Solid–Liquid Equilibria in the Quaternary Systems KCl–KBr–K2B4O7–H2O and KCl–KBr–K2SO4–H2O at 373 K

Solid–liquid equilibria in the quaternary systems KCl–KBr–K2B4O7–H2O and KCl–KBr–K2SO4–H2O at 373 K were measured by the isothermal solution saturation method. The equilibrium solid phases, solubilities of salts, and densities of saturated solutions in the two systems were determined. The experimental data are used to plot the solubility diagrams, water content diagrams, and solution density diagrams of the two systems. It was found that both systems contain the solid solution of KCl and KBr [K(Cl,Br)], so their solubility diagrams have no invariant point, but each has a univariant curve and two crystallization regions. In the first system, the solids are K(Cl,Br) and potassium borate aquahydrate (K2B4O7·4H2O), and in the second system, the solids are K(Cl,Br) and potassium sulfate (K2SO4).

Selective removal mercury (II) from aqueous solution using silica aerogel modified with 4-amino-5-methyl-1,2,4-triazole-3(4H)-thion

Silica aerogel surface modifications with chelating agents for adsorption/removal of metal ions have been reported in recent years. This investigation reported the preparation of silica aerogel (SA) adsorbent coupled with metal chelating ligands of 4-amino-5-methyl-1,2,4-triazole-3(4H)-thion (AMTT) and its application for selective adsorption of Hg(II) ion. The adsorbent was characterized by Fourier transform infrared spectra (FTIR) and thermo gravimetric analysis (TGA) measurements, nitrogen physisorption and scanning electron microscope (SEM). Optimal experimental conditions including pH, temperature, adsorbent dosage and contact time have been established. Langmuir and Freun- dlich isotherm models were applied to analyze the experimental data. The best interpretation for the experimental data given by the Langmuir isotherm equation and the maximum adsorption capacity of the modified silica gel and silica aerogel was 142.85 and 17.24 mgg �1 , respectively. Thermodynamic parameters such as Gibbs free energy (∆G o ), standard enthalpy (∆H o ) and entropy change (∆S o ) were investigated. The adsorbed Hg(II) on the SA-AMTT adsorbents could be completely eluted by 1.0 M KBr solution and recycled at least four times without the loss of adsorption capacity. The results of the present investigation illustrate that modified silica aerogel with AMTT could be used as an adsorbent for the effective removal of Hg(II) ions from aqueous solution.

In search of brominated activated carbon fibers for elemental mercury removal from power plant effluents

Three methods have been developed to incorporate bromine containing groups into activated carbon fibers (ACFs) involving the use of bromine vapor, KBr impregnation and electrochemical methods using KBr solution. Both static and dynamic tests were carried out to measure the elemental mercury adsorption performances of these brominated samples. XPS and BET tests of these brominated ACFs have also been conducted. For our brominated samples, bromine atoms were incorporated into the carbon matrix which increased Hg0 uptake capacities when compared to raw ACF samples. A possible mechanism for elemental mercury adsorption, which is likely to involve the formation of oxidized mercury complexes (e.g. [HgBr]+, [HgBr2] and [HgBr4]2−), is also discussed. For the brominated samples treated by Br2 vapor and electrochemical methods, they showed stable Hg0 adsorption performance (30% to 33% removal) up to 3 months, which are very promising for commercialization.

Rapid determination of ultra-trace amounts of acrylamide contaminant in water samples using dispersive liquid–liquid microextraction coupled to gas chromatography-electron capture detector

The objective of the present study was to develop and validate a rapid, highly sensitive, and reliable extraction method to determine acrylamide in water samples. The method was based on the derivatisation of the acrylamide in the presence of KBr, HBr and saturated Br2 solution into 2,3-dibromopropionamide and dispersive liquid–liquid microextraction (DLLME) followed by gas chromatography–electron capture detection (GC–ECD) of the analyte. Different parameters that affect the DLLME process such as types and volumes of disperser solvent, ionic strength of aqueous solution and extraction time were investigated and optimised. Under optimal conditions, excellent linearity was obtained between concentration of acrylamide and the response of ECD with correlation of determination (R2) of 0.9999. The precision of the method, which was determined by calculating the relative standard deviations (RSD) of the at least three replicate measurements, was 3.6%. The method presented in this study is sensitive enough for the determination of acrylamide in different water samples with the limit of detection (LOD) value of 1 ng L−1. The mean percentage recoveries exceeded 91% for all of spiking levels in the real water samples. The results obtained from DLLME method are validated by EPA method 8032A.

Adsorption of cationic surfactants on covered hanging mercury drop electrode surface of variable area

Cetyldimethylbenzylammonium chloride (CDBACl) or cetyltrimethylammonium bromide (CTAB) is preadsorbed on mercury and used as substrate. The adsorptive stripping voltammetry with the two-step procedure is used. The mercury droplet with the preadsorbed surfactant is expanded in aqueous solutions of KCl, KBr, CTAB, CDBACl, or cetylethyldimethylammonium bromide (CEDAB). The surface area was increased from 0.0022cm2 up to 0.0571cm2. The surfactant molecules are maintained close to each other and in the vicinity of the electrode by the applied electric field. The expanding of the droplets resulted in a reorientation of the adsorbed molecules depending on the surfactant surface concentration. In some cases, condensed films were observed. Differences were noticed in the adsorption and desorption potential region. A linear increase in the capacitance current with the surface area was found in all cases up to a maximum increase in the surface area. Partly disorganized films were also observed. In some cases, defects were noticed during expansion. In one case, fractal structure was observed.

Joint Effect of Anogessius Leocarpus Gum (AL Gum) Exudate and Halide Ions on the Corrosion of Mild Steel in 0.1 M HCl

In an attempt to improve the corrosion inhibition potential of Anogessius leocarpus gum exudates for mild steel in solutions of HCl, corrosion inhibition efficiencies of the gum, KI, KCl, and KBr were determined experimentally using weight loss and gasometric methods. 0.05 M KI, 0.05 M KBr and 0.05 M KCl were combined with various concentrations of Anogessius leocarpus gum and their combined inhibition efficiencies were used in computing synergistic parameters for the respective combinations. The results obtained indicated that combination of 0.4 and 0.5 g/L of AL gum with 0.05 M solutions of KI and KBr, respectively, enhanced inhibition efficiency of the gum. However, for all concentrations of AL gum, combinations with 0.05 M KCl recorded a remarkable increase in inhibition efficiency, but calculated values of the synergistic parameter indicated that the adsorption of AL gum on mild steel surface is antagonized by the presence of Cl - . Theory of competitive and co-operative adsorption has been used to explain the co-adsorption of the gum and the halides. From calculated values of activation energy (< 80kJ/mol), free energy of adsorption (< -40 kJ/mol) and the variation of inhibition efficiency with temperature, the adsorption characteristics of the gum, halides and that of gum-halide mixtures were found to be consistent with the mechanism of physical adsorption. The adsorption was also found to be endothermic, spontaneous and favored the Langmuir adsorption model.

The role of the medium in electrochemical functionalization and dispersion of carbon nanotubes

An electrochemical method for dispersion of single-walled carbon nanotubes (SWNTs) is described. The technique is based on grafting of oxygen-containing functional groups to the nanotube surface during electrolysis in aqueous and nonaqueous potassium bromide solutions. A dependence of the degree of functionalization of nanotubes on the solvent was revealed experimentally. Nanotubes treated in DMSO have about 14 carbon atoms per oxygen atom from functional groups (cf. nearly four C atoms per oxygen atom in the nanotubes treated in aqueous solutions). The corresponding maximum specific capacities of the electrodes are nearly 10 and 60 F g−1. The samples treated in solutions of KBr in DMSO have about 300 carbon atoms per bromine atom on the nanotube surface (cf. only 30 carbon atoms in the samples treated in aqueous solution). A mechanism of electrochemical modification of SWNTs is proposed. Its key step is production of atomic oxygen that oxidizes the nanotube surface with the formation of functional groups.

Comparison of two sensors ECH&lt;sub&gt;2&lt;/sub&gt;O EC-5 and SM200 for measuring soil water content

The goal of this study was calibration of the ECH&lt;sub&gt;2&lt;/sub&gt;0 soil moisture sensor EC-5 and the sensor SM200 for selected soils of the Czech Republic. Based on the soil maps of the Czech Republic and various climatic conditions, five humic horizons of different soil types were selected: Stagnic Chernozem Siltic, Haplic Chernozem, Chernozem Arenic, Haplic Luvisol, and Haplic Cambisol. Soil properties (pH&lt;sub&gt;KCl&lt;/sub&gt;, pH&lt;sub&gt;H2O&lt;/sub&gt;, exchangeable acidity, cation exchange capacity, hydrolytic acidity, basic cation saturation, sorption complex saturation, oxidable organic carbon content, CaCO&lt;sub&gt;3&lt;/sub&gt; content, salinity, sand, silt, and clay content, soil particle density, bulk density) were determined using the standard laboratory techniques. Six ECH&lt;sub&gt;2&lt;/sub&gt;0 EC-5 sensors permanently installed in six 606 cm&lt;sup&gt;3&lt;/sup&gt; repacked soil samples of each soil were calibrated. Four calibrated SM200 sensors were inserted into the same soil samples only when measuring sensor signal. Soil water contents were determined gravimetrically. Linear equation was used to find parameters of the calibration equations relating sensor signals or evaluated dielectric constants and soil water contents. The multiple linear analyses showed that the parameters of the calibration equations for the EC-5 depended on the bulk density, fraction of sand particles, and salinity. Parameters a and b of the SM200 depended on the initial soil salinity, sand fraction and CaCO&lt;sub&gt;3&lt;/sub&gt; content, and on the sand fraction, respectively. The impact of KBr solute (concentrations of 0.01, 0.05 and 0.1M Br) on calibration equations was studied as well. It was found that ECH&lt;sub&gt;2&lt;/sub&gt;0 EC-5 sensor measurements were more influenced by KBr solution than SM200 measurements. In the case of the ECH&lt;sub&gt;2&lt;/sub&gt;0 EC-5 sensor, impact of KBr was lower in soils of higher initial salinity. SM200 measurements were noticeably influenced only when 0.1M Br solution was applied.

Temperature‐concentration oscillations of crystal‐solution phase equilibria in the presence of trace impurities of surface‐active agents

AbstractUsing the examples of aqueous salt solutions NaNO3, KNO3, RbNO3, K2SO4, NaBr·2H2O, KBr, and NH4NO3, it was experimentally proven that the new phenomena, i.e. temperature‐concentration oscillations of crystal‐solution phase equilibria detected previously in the range of 15–45 °C remain in the presence of trace impurities (10‐4–10‐3 wt. %) of ion‐active organic matters. The signs of breaks transformation into pair oscillations of “maximum‐minimum” type are established for the K2SO4, NaBr, KBr solutions. The efficiency of influence of trace impurities on phase equilibria sharply rises in the areas of the temperature‐concentration oscillations (the saturation temperature ranges up to 10 K). The impurity efficiency is promoted by the presence of the amides in its content (as compared with the sulphates) and an increase in length of the hydrocarbon radical. The phenomenon is absent in case of an addition of ion‐inactive compounds. (© 2011 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Ionic liquid salt bridge based on N-alkyl-N-methylpyrrolidinium bis(pentafluoroethanesulfonyl)amide for low ionic strength aqueous solutions

The phase-boundary potential between the moderately hydrophobic ionic liquid and a low ionic strength aqueous solution is demonstrated to be stable and constant with the standard deviation of 0.4 mV down to 20 μmol kg −1 HBr, LiBr, and KBr solutions, for three ionic liquids that consist of either N -methyl- N -octylpyrrolidinium, N -heptyl- N -methylpyrrolidinium, or N -hexyl- N -methylpyrrolidinium and a common anion species, bis(pentafluoroethanesulfonyl)amide. This stability is promising for accurate measurements of pH of low ionic strength samples and reliable estimates of single ion activities in general. The phase-boundary potential deviates from the value determined by the partition of the ionic liquid in further dilute aqueous solutions. The magnitude of the deviation ranges from 3 to 11 mV at 5 μmol kg −1 MBr (M is H + , Li + , or K + ). The solubility of these ionic liquids in water is 0.2 mmol dm −3 at most at 25 °C, which is another advantage of ionic liquid salt bridge in electroanalytical chemistry.

New Insights into Buffer-Ionic Salt Interactions: Solubilities, Transfer Gibbs Energies, and Transfer Molar Volumes of TAPS and TAPSO from Water to Aqueous Electrolyte Solutions

The solubilities of N-[tris(hydroxymethyl)methyl]-3-aminopropanesulfonic acid (TAPS) or N-[tris(hydroxymethyl)methyl]-3-amino-2-hydroxypropanesulfonic acid (TAPSO) in water and in aqueous solutions of CH3COOK (KAc), KBr, KCl, or NaCl were determined from density measurements at 298.15 K. The solubilities of TAPS in aqueous solution decrease with increasing concentration of the salts (salting-out effect), whereas those of TAPSO increase with increasing concentration of the salts (salting-in effect). The solubility and density data were further used to calculate the apparent transfer Gibbs energies, ΔtrG, and transfer molar volumes, \(\Delta_{\mathrm{tr}}V_{\phi}^{\mathrm{o}}\), of these buffers from water to aqueous electrolyte solutions at 298.15 K. The contributions of various functional groups of TAPS, TAPSO, and the related buffers (tris(hydroxymethyl)aminomethane, TRIS, and N-tris[hydroxymethyl]-4-amino-butanesulfonic acid, TABS) to the transfer properties were systematically estimated from the calculated ΔtrG and \(\Delta_{\mathrm{tr}}V_{\phi}^{\mathrm{o}}\).

CO 2 attraction by specifically adsorbed anions and subsequent accelerated electrochemical reduction

The electrochemical reduction of CO 2 was studied on a copper mesh electrode in aqueous solutions containing 3 M solutions of KCl, KBr and KI as the electrolytes in a two and three phase configurations. Electrochemical experiments were carried out in a laboratory-made, divided H-type cell. The working electrode was a copper mesh, while the counter and reference electrodes were Pt wire and Ag/AgCl electrode, respectively. Results of our work suggest a reaction mechanism for the electrochemical reduction of CO 2 in the two phase configuration where the presence of Cu-X as the catalytic layer facilitates the electron transfer from the electrode to CO 2. Electron-transfer to CO 2 may occur via the X ad −(Br −, Cl −, I −)–C bond, which is formed by the electron flow from the specifically adsorbed halide anion to the vacant orbital of CO 2. The stronger the adsorption of the halide anion to the electrode, the more strongly CO 2 is restrained, resulting in higher CO 2 reduction current. Furthermore, it is suggested that specifically adsorbed halide anions could suppress the adsorption of protons, leading to a higher hydrogen overvoltage. These effects may synergistically mitigate the overpotential necessary for CO 2 reduction, and thus increase the rate of electrochemical CO 2 reduction.

Caracterização hidrodispersiva de dois solos da região irrigada do Vale do São Francisco

A caracterização hidrodispersiva de um Latossolo e de um Neossolo Quartzarênico, ambos da região do Vale do São Francisco, foi realizada em laboratório por meio de ensaios de deslocamento de líquidos miscíveis em colunas de solo deformado. Os ensaios compreenderam o deslocamento de um pulso de 1,0 volume de poros da solução de KBr nas vazões de 2,4.10-5; 4,8.10-5; 7,2.10-5; 9,6.10-5 e 1,2-10-4 m³ h-1 e nas concentrações de 11,89; 59,49 e 118,99 g L-1, e três repetições para cada ensaio, sob condições de saturação e fluxo em regime estacionário. Por meio do programa CXTFIT 2.0, que ajusta a solução analítica da equação do modelo convectivo-dispersivo (CDE) aos pontos da curva experimental de eluição, foi possível obter os parâmetros hidrodispersivos do fator de retardamento (R) e o coeficiente de dispersão hidrodinâmica (D). O modelo CDE realizou um bom ajuste aos pontos das curvas de eluição, com valores dos coeficientes de determinação variando de 98 a 99% para ambos os solos; os valores de R ficaram próximos a 1,0 nos dois solos, indicando que o KBr não interage com os mesmos e a dispersividade do Neossolo é maior que a do Latossolo devido a distribuição do tamanho dos poros ser maior no Neossolo.

Volumetric properties of MES, MOPS, MOPSO, and MOBS in water and in aqueous electrolyte solutions

4-Morpholineethanesulfonic acid (MES), 4-morpholinepropanesulfonic acid (MOPS), 3-morpholino-2-hydroxypropanesulfonic acid (MOPSO), and 4-( N-morpholino)butanesulfonic acid (MOBS), are useful for pH control as standard buffers in the physiological region of 5.5–6.7 for MES, 6.5–7.9 for MOPS, 6.2–7.6 for MOPSO, and 6.9–8.3 for MOBS, respectively. On the basis of density measurements at 298.15 K, the apparent molar volumes, V ϕ , of the above-mentioned buffers in water and in (0.05, 0.16, and 0.25) mol kg −1 aqueous solutions of NaCl, KCl, KBr, and CH 3COOK have been calculated. The partial molar volumes at infinite dilution, V ϕ o , obtained from V ϕ , have been used to calculate the volume of transfer, Δ t r V ϕ o , from water to aqueous electrolyte solutions. It was found that both V ϕ o and Δ t r V ϕ o vary linearly with increasing the number of carbon atoms in the alkyl group side chain of the zwitterionic buffers. These linear correlations have been utilized to estimate the contributions of the zwitterionic end group (morpholinium ion, –SO 3 −) and –CH 2– group to V ϕ o and Δ t r V ϕ o . The values of V ϕ o and Δ t r V ϕ o for some functional group contributions of the zwittierionic buffers with salts have also been reported.

電解発生‐臭素付加法によるニッケルめっき液中２‐ブチン‐１，４‐ジオールの定量分析

A method for addition of electrolytically generated bromine was applied for determination of 10-100 g m−3 of 2-butyne-1,4-diol in a nickel-plating solution. Distinct from existing methods, this method generates bromine electrolytically from a KBr solution before each analysis. Amounts of bromine generated using electrolysis agreed with the theoretical value using 1.5 M HCl in a KBr solution. Bromine addition to 2-butyne-1,4-diol was completed with more than 30 min reaction time. Additionally, blank correlation was necessary because small amounts of bromine disappeared during the reaction. It was possible to determine 2-butyne-1,4-diol in nickel plating solutions based on the findings described above. The lower limit of around 5 g m−3 was achieved. This method was not influenced by main components of the nickel-plating solution. However, the presence of allylsulfonic acid as a brightening agent elevated the quantitative values of 2-butyne-1,4-diol. Further investigation revealed that allylsulfonic acid reacts with bromine quantitatively and too rapidly. Results show that the selective determination of 2-butyne-1,4-diol and allylsulfonic acid in a nickel-plating solution became possible using different reaction times for brightening agents and bromine.

Low-Frequency Isotropic Raman Spectra of Concentrated Aqueous KX (X: Cl, Br, NO3, and SCN) Solutions

Abstract Polarized Raman spectra for concentrated aqueous KX solutions (X: Cl, Br, NO3, and SCN) were measured in the frequency range of 30 ≤−1 in order to find the totally symmetric stretching vibrational mode of hydrated K+. The observed polarized peak intensities of the intermolecular vibrational mode at−1 in the isotropic spectra for KCl and KBr solutions exhibit systematic increase with increasing solute content. Polarized components at−1 were observed in the isotropic spectra for 5 mol % KNO3 and 7 mol % KSCN solutions, respectively. The position of these polarized peaks were found to shift to lower frequency by 7–15 cm−1 in D2O solutions, which is consistent with the expected value of the H/D isotopic shift calculated for the totally symmetric vibrational mode of the hydrated K+, K+(H2O)6.≤ 1000 cm= 160–180 cm= 166 and 167 cm