using the evaporating method, the solubility of potassium nitrate was determined in various mixtures containing water and ethanol at 25°c. the results show that the solubility of kno3 decreases with increasing the mass percent of ethanol in the mixtures. this trend is along with decreasing the dielectric constant of water+ethanol mixtures. moreover, it can be concluded that the totqal solubilit...

The ion-pair association constant values, related to the reaction +  were determined by means of the NMR spectroscopy. The values of the thermodynamic functions of the ion pairing process were calculated on the basis of the NMR results. In addition, the association entropy was found to be dependent on the temperature. Comparing the experimental data and the Fuoss theory it is found that  ion-pa...

the solubility of kno3 in the mixed solvent (water 85%+methanol 15%) were determined by using solvent evaporating method at different temperatures (25, 30, 40, 50, 60 ;c). in addition the equilibrium constant of ion pair formation, kip, for k+no3 – ion-pair on the basis of fuoss contact ion pair model was calculated. upon choosing the extended debye-hückel model for estimating the mean activity...

The solubility of KNO3 in the mixed solvent (water 85%+methanol 15%) were determined by using solvent evaporating method at different temperatures (25, 30, 40, 50, 60 ;C). In addition the equilibrium constant of ion pair formation, KIP, for K+NO3 – ion-pair on the basis of Fuoss contact ion pair model was calculated. Upon choosing the extended Debye-Hückel model for estimating the mean activity...

in this article, theoretical studies on the selective complexation of the halide ions (f¯, cl¯ and br¯) and ion pairs (na+f¯, na+cl¯ and na+br¯) with the cyclic nano-hexapeptide (cp) composed of l-proline have been performed in the gas phase. in order to calculate the dispersion interaction energies of the cp and ions, dft-d3 calculations at the m05-2x-d3/6-31g(d) level was employed. based on t...

A simple, accurate and fast vortex-assisted dispersive liquid-liquid microextraction procedure has been developed for the extractive spectrophotometric determination of niflumic acid in biological samples. The method is based on the formation of an ion association complex between niflumic acid and methylene blue. The resulting ion-pair was extracted into dichloromethane and its absorbance was m...

In the present work, we have studied ion-pair states of matrix-isolated I(2) with vacuum-UV absorption and UV-vis-NIR emission, where the matrix environment is systematically changed by mixing Kr with Xe, from pure Kr to a more polarizable Xe host. Particular emphasis is put on low doping levels of Xe that yield a binary complex I(2)-Xe, as verified by coherent anti-Stokes Raman scattering (CAR...

a simple, precise, rapid and low-cost potentiometric method for diclofenac determination in pharmaceuticals is proposed. a new diclofenac-sensitive electrode was constructed by incorporating the diclofenac ion pair complex with butyl rhodamine b into graphite matrix. the electrode exhibited a linear response over the concentration range of 1 × 10-4 – 5 × 10-2 mol l-1, a detection limit of 3.9×1...

An extractive spectrophotometric method is described for the assay of sitagliptin phosphate in bulk drug and in tablets. Sitagliptin phosphatewas extracted as an ion-pair complex from the solution containing Eriochrome black T and 0.1N HCl into chloroform and the absorbance of the complex was measured at 500nm.The working conditions of the method were investigated and optimized. Beer’s law plot...

The interactions two synthetic triazinyl reactive dyes Mono-s-chloro Triazinyl reactive dyes DI and DII with the cationic surfactant N-hexadecyl pyridinium chloride CPC were studied using a conductometric method in 25, 30, 35, 40 and 45ºC. The equilibrium constants and other thermodynamic parameters for the ion pair formation were calculated on the basis of a theoretical model using the data ob...