KI Solutions Research Articles

Relative sound velocities of sea salts at 25°C

The relative sound velocities (u−u0) of aqueous HCL, LiCL, NaF, NaCL, NaBr, NaI, NaNO3, NaOH, NaHCO3, Na2SO4, KF, KCL, KBr, KI, KNO3, K2CO3, K2SO4, RbCl, CsCl, NH4Cl, NH4Br, MgCl2, CaCl2, SrCl2, BaCl2 and MgSO4 solutions were measured from 0.01 to 1.0 at 25°C. The sound velocities were fitted to a function of molality (maximum standard deviation 0.05 m sec−1) u=u0+Am+Bm(3/2)+Cm2, where u0 is the sound velocity in pure water, and A, B, and C are temperature dependent parameters. The adiabatic compressibilities βS were determined from the sound velocities and were used to calculate the adiabatic apparent molal compressibilities φK(S) of the salts. The φK and βS of seawater were estimated by using Young’s rule. The calculated values of φK and βS agree with those determined from the measurements on seawater solution to ±0.18×10−4cm3mol−1bar−1 and ±0.004×10−6bar−1. The sound speeds of seawater calculated from the values of βS estimated from Young’s rule agree on the average to ±0.02m sec−1 (maximum standard deviations 0.07 m sec−1) with the direct measurements of Millero and Kubinski.

The Structure of the First Hydration Sphere of Ions in Electrolyte Solutions A Nuclear Magnetic Relaxation Study

AbstractThe magnetic 1H‐relaxation rate in aqueous solutions of LiCl, NaCl, RbCl, CsCl, and KI was measured in order to evaluate the nuclear magnetic proton‐ion relaxation contribution using the isotopic dilution technique. Furthermore, the temperature dependence of these relaxation rates was examined. It turned out that for Rb+, Cs+, and I− the proton‐ion relaxation rate consists of two parts: an intermolecular spin‐rotation contribution and a magnetic dipole‐dipole contribution. The first one increases and the second one decreases with increasing temperature. — From the dipole‐dipole rate the proton ion distances were computed using suitable ion‐proton model pair distribution functions.

The effect of structure on self-diffusion in concentrated electrolytes : relationship between the water and ionic self-diffusion coefficients

Self-diffusion coefficients of water (HTO) in aqueous solutions of KI, KCl and CsCl at 25 and 10 °C are reported. For the KCl and CsCl solutions the self-diffusion coefficients of the cations and anions are also given. Then, formal expressions are derived which interconnect the water and the ion self- diffusion coefficients in the same solution. It is shown that the experimental data fit satisfactorily in the framwork given by the theory.

RELATIONSHIP BETWEEN CONTRACTILITY AND SOME BIOCHEMICAL PROPERTIES OF MYOFIBRILS PREPARED FROM NORMAL AND PSE PORCINE MUSCLE

ABSTRACTContractility and ATPase activity of myofibrils from normal and PSE porcine muscles were studied Studies were also made on the extractability of proteins from myofibrils isolated from normal and PSE muscles. Normal muscles contracted instantaneously after the addition of Mg2+‐ATP, while PSE muscles contracted in part or did not contract. ATPase activity of myofibrils isolated from muscle having higher pH value was higher than that of myofibrils isolated from muscle having lower pH value. When using either Hasselbach‐Schneider or KI solutions to extract myofibrillar proteins, the proportion of protein extracted was significantly higher for normal muscles when compared to those from PSE muscles.

Effect of ions on phospholipid layer structure as indicated by Raman Spectroscopy

Various anions and cations are found to induce changes in the layered structure of phosphatidylcholine-water systems as indicated by Raman Spectroscopy. From the ratio of Raman intensities, I 1064 I 1089 , it is inferred that dispositive ions decrease the proportion of gauche character in the hydrocarbon chains, with the relative influence being: Ba 2+ < Mg 2+ < Ca 2+ ≈ Cd 2+. Unipositive ions (Li +, K + and Na +) produce no observed changes in the Raman spectrum of the lecithin dispersion. The proportion of gauche character of the hydrocarbon chains is found to be nearly independent of the anion for: Br −, Cl −, acetate −, I −, ClO 4 −, CNS − and SO 4 2−. Dispersions prepared with a solution of KI + I 2 produced Raman spectra in which the 1089 cm −1 peak, which is characteristic of random lipid chains, was greatly intensified, presumably because of the presence of I 3 − which is known to penetrate the lipid lamellae. The observed trends are discussed.

A procedure for simultaneous preparation of large amounts of DNA and RNA by the use of potassium lodide gradients

A method is described that permits the isolation of both DNA and RNA from tissues on KI density gradients without destroying either nucleic acid species. Up to 3 mg can be resolved efficiently in a single 13-ml gradient. Data are presented which show that direct monitoring of the OD of nucleic acids in KI solutions is possible without addition of ethidium bromide. Furthermore, equations for the correlation of density, refractive index and weight per volume are presented.

The phases of the AgI–KI–H2O system

An X-ray diffraction study of the AgI–KI–H2O chemical system was conducted by injecting an acetonic solution of a 2:1 mole ratio of AgI:KI directly upon an inert substrate thermally strapped to a thermoelectric cold stage. The atmosphere over the stage was controlled from 0.6 mb water vapor pressure to saturation while the temperature was varied from −22 to 25°C. Under these conditions four distinct crystalline phases are formed. Crystals of phase AK (KAg4I5) appear as the acetone evaporates. Moisture available from the ambient atmosphere functions as a catalyst as the newly formed AK transforms to phase BK (K2AgI3). At higher vapor pressures a second transformation results in phase CK. All phases break down and form an aqueous solution of KI plus equant AgI crystals (complex DK) at saturation vapor pressures. Another hydrous phase EK occurs below 0°C. The most probable composition of phases CK and EK is KAg2I3.H2O and KAg3I4.8H2O respectively. Nucleation studies show that the KI system is a poorer artificial nucleant of ice than the NH4I–AgI system above −10°C. Kinetics of the system suggest an absence of any free AgI for aerosols released from airborne platforms or from ground seeding stations.

ChemInform Abstract: STRUCTURE OF AQUEOUS SOLUTIONS. INFRARED SPECTRA OF THE WATER LIBRATIONAL MODE IN SOLUTIONS OF MONOVALENT HALIDES

AbstractDie Änderungen der IR‐Librationsmoden von Wasser in Abhängigkeit der zugegebenen Salzmenge werden bei 30°C in NH4F‐, NH4Cl‐, NH4Br‐, NH4J‐, LiCl‐, LiBr‐, NaCl‐, NaBr‐, NaJ‐, KCl‐, KBr‐ und KJ‐Lösungen untersucht.

Activity coefficients of potassium perrhenate in aqueous mixtures with KCl, NaCl and KI at 298.15 K

The solubilities of potassium perrhenate in aqueous NaCl, KCl and KI solutions are reported. The solubility activity product for this electrolyte was determined using extrapolation functions involving three different mean ionic activity coefficient expressions. Mean ionic activity coefficients have been computed for potassium perrhenate in dilute aqueous solutions and there is no justification for considering ion association1,2 in these solutions.

Structure of aqueous solutions: Infrared spectra of the water librational mode in solutions of monovalent halides

The variations of the infrared librational mode of water with concentration of added salt have been examined at 30�C for solutions of NH4F, NH4Cl, NH4Br, NH4I, LiCl, LiBr, NaCl, NaBr, NaI, KCl, KBr and KI. The data indicate that water in the primary hydration sheath can be distinguished from the remainder of the water and primary hydration numbers have been estimated. It is shown that in general the larger the ion the greater the change to the spectral band. The ammonium fluoride is shown to be unique in producing little disturbance of the water structure.

γ and dγ/dT measurements on aqueous solutions of 1,1-electrolytes

Measurements of the surface tension, γ, and its temperature derivative, dγ/ dT, have been made by means of Wilhelmy slide techniques for dilute (≤ 1.5 m) aqueous solutions of NaCl, KCl, NaI, and KI. Using the data obtained, the thermodynamic surface zone properties have been evaluated for a surface phase containing only the water component. The results show that the distance of approach to the Gibbs dividing surface Σ (H 2O) is approximately independent of the salt concentration and that it is smaller for the iodide ions than for the chloride ions due to differing modes of interaction with the surface zone water molecules. The possibilities of ion interaction with the uppermost layer of water molecules appear to be of particular importance and are strongly dependent on the polarization properties of the ions. Qualitative agreement is found with results of NMR quadrupole relaxation studies of anion interactions with the cage water layers formed at the hydrophobic cations in aqueous solutions of alkylammoniumhalides.

Positron annihilation in aqueous solutions of KMnO4 and KI

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Reaction of the solvated electron with organic halides

Studies of the competition for hydrated electrons between N 2 O and on organic halide, X, Rperformed by measuring the N 2 yields from the ultra-violet illumination of KI solutions containing these two solutes, lead to values of the relative rate constant in complete disagreement with the ratio of the absolute rate constants obtained by pulse radiolysis. This disagreement is found to persist when methanol is used as solvent, when (in aqueous solution) the hydrated electrons are generated by γ-radiolysis, and when N 2 O is replaced by H +. It is thus deduced that there is some mechanistic complication in the reactions and it is demonstrated that the data are more consistent with the scheme previously postulated by us than with one analogous to that suggested by other workers as operative in some gas-phase systems. In the radiation chemical studies, high yields of X − ion are found from all solutes, RX. The mechanism postulated by Teplý in regard to CHCl 3 does not appear adequate to explain the high yield of X − from various RX and in the presence of OH scavengers. Their occurrence means that, mechanistic complications apart, relative rate constants cannot properly be deduced from halide yields in systems containing another solute.

Magneto optical rotatory dispersion studies of simple electrolyte solutions. Part 2.—Measurements on solutions of NaBr, KBr, NaI and KI

The m.o.r.d. of concentrated aqueous solutions of NaBr, KBr, NaI and KI were measured in the wavelength region 350–600 nm. The variation of the specific rotations of the solutions with concentration of solute could be interpreted in terms of the competing processes of solvent structure-making and structure-breaking. The changes in rotation with wavelength were fitted to a non-term Drude equation and the constants of this equation, K and λ0, claculated by the Biot–Lowry, the Yang–Doty and the Heller methods. It was evident, however, that λ0 could not be identified with the peak position of an absorption band and that the Drude equation is merely a convenient empirical relationship for the m.o.r.d. results in the wavelength range studied. The variation of K with solute concentration was compatible with the relative effects of cations and anions on solvent structure. The magnetic rotations due to the solutes were calculated in three different ways and were related to the known properties of the solutes.

X-ray structural investigation of aqueous solutions of KI and LiI

X-ray structural investigation of aqueous solutions of KI and LiI

ChemInform Abstract: THE EFFECTS OF POTASSIUM FLUORIDE AND POTASSIUM JODIDE ON THE EXPANSIVITY OF WATER

An examination of the specific volumes of K F and KI solutions over the concentration range 0.1 t o 2.0 171 and over the temperature range 0 to 95' has led to the conclusion that the partial molal expansivity of the salts is due almost entirely to changes in the electrostrictive processes in water with temperature and are not due to changes in the structural effects of the salts on the bulk water with changing temperature. However, structural effects are considered to be of significant magnitude below 70.

The Effects of Potassium Fluoride and Potassium Iodide on the Expansivity of Water

An examination of the specific volumes of KF and KI solutions over the concentration range 0.1 to 2.0 m and over the temperature range 0° to 95° has led to the conclusion that the partial molal expansivity of the salts is due almost entirely to changes in the electrostrictive processes in water with temperature and are not due to changes in the structural effects of the salts on the bulk water with changing temperature. However, structural effects are considered to be of significant magnitude below 70°.

Depolarized Rayleigh-wing scattering in water and aqueous electrolytic solutions

Depolarized Rayleigh-wing scattering has been studied in the region 20–110 cm−1 in pure H2O and aqueous KI and MgSO4 solutions, for temperatures between 0 and 90°C and concentrations in the 0–3M range (0–1M for MgSO4). The integrated intensity increases faster with temperature in pure H2O than would be expected from the collision-induced polarizability theory of Bucaro and Litovitz. We ascribe this excess to temperature-induced structural changes (the breaking of hydrogen bonds). The integrated intensity in KI solutions increases with concentration and in MgSO4 solutions decreases slightly with concentration. This is also discussed in terms of structural enhancement or breakdown.

Sonochemical yields of cavitation centres at 1 MHZ

Solutions of KI, CCl 4 , and starch have been irradiated at 1 MHz in a focused ultrasonic field. The electrical voltage signals which appear at the transducer electrical terminals, superimposed on the drive signal, and which have previously been associated with acoustic cavitation in sonicated water, have been monitored together with the chemical changes occurring. When solutions were irradiated in a 3·3 ml container at the focal position a chemical yield was obtained in some samples irradiated at peak focal intensities of 50–388 W/cm 2 , but the reproducibility of results was poor. At an intensity of 515 W/cm 2 many Willard type cavitation events occurred (i.e., microbubble clouds moving through the focus and lasting for milliseconds). They were accompanied by electro-acoustic signals of the order of volts. The chemical yield correlated with the appearance of Willard events and iodine was being produced at an average rate of 2·8×10 10 molecules per cycle of the sound wave during an event. However, when larger volumes, from 43 ml to 7·5 litres, were irradiated at intensities less than 515 W/cm 2 , the iodine yield increased dramatically, being 6000 times larger in a 260 ml container than in a 3·3 ml one at 175 W/cm 2 . The occurrence of a high yield was related to the appearance of a continuous cavitation signal of the order of 50 millivolts. The active centres could be detected as origins of streams of blue in the container. It is suggested that they are trapped in the sound field in the same manner as visible bubbles are trapped. A centre could remain active for 20 seconds compared with the millisecond lifetime of a Willard event and have a yield of about 10 9 molecules per cycle of the sound wave at 140 W/cm 2 . The position of maximum activity is downstream from the focus and it is shown that nuclei do not need to pass through the high intensity focal region before acting as cavitation centres.

Effect of Supporting Electrolytes on the Tensammetric Waves of t-Pentyl Alcohol

It is widely recognized that supporting electrolyte has an important effect on adsorption, but few syStematie studies have been done hitherto. The authors investigated the effect of supporting electrolyte on the adsorption of organic compounds at electrode. Tensammetriq waves were measured by Yanagimoto Polarograph PA-102, and drop time-potential curves, were used for analyses of the effect.Tensammetric waves of O.05 mol/l of t-pentyl alcohol (constant coneentratlQp). were measured varying the supperting electrolyte conentration. ln such a case, two effects are considered. One is salting out effect which increases the adsorption of organic compounds on electrode. The other is ionic specific adsorption which either reduces the adsorption of organic compounds on electrode or narrows the adsorption potential region-potential region between two adsorption desorption peak, poten-tLigls (E, r, E-p)In the solution of KF or NH2SO4, salting out effect outweighed the other, so that the adsorption potential region and adsorptio:n-desorption peak heights lp, Ip increased with the elevation of electrolyte concentration (Fig. 1, Fig. 2 and Fig. 4). ln the solution of KI or KSCN, ionic specific adsorption outweighed the other, so that the adsorption potential region and peak heights decreased with the elevation of electrolyte concentration (Fig. 5, Fig. 6 and Fig. 7). ln the solution of KCI or KBr, both effects existed. Up to about 1 N solution, ionic specific adsorption narrowed the adsorption potential region (Fig. 8 and Fig.9), while salting out effect increased the surface excess in the adsorption potential region (Fig.10). Above 1 N solution, salting effect outweighed the other and both surface excess and adsorption potential region increased.