Alina Piekarska

Electrical Conductivity of NaI Solutions in Methanol—n-Propanol and Methanol—Isopropanol Mixtures at 298.15 K The Effect of Ion Association on the Standard Dissolution Enthalpies of NaI

Abstract The electrical conductivity of NaI solutions in binary methanol-n-propanol and methanol-isopropanol mixtures within the whole composition range has been measured and analysed using the Fuoss-Justice equation. The dependence of the equilibrium constants of ion-pair formation and the Walden products on the mixed solvents composition in studied systems has been discussed. The standard dissolution enthalpies of NaI in the same binary mixtures (published earlier) have been recalculated taking into account the ion-association process.

Calorimetric studies of NaI solutions in binary organic isodielectric mixtures

Enthalpies of NaI solution in methanol mixtures with nitromethane (NM), N,N-dimethylformamide (DMF) and acetonitrile (ACN) were measured at 298.15 K in the entire range of mixture compositions. The standard solution enthalpy in methanol–DMF has a monotonic character, while in the case of the MeOH–NM system it exhibits a maximum in the region of high methanol content. The most complex character of the solution enthalpy plot with a large minimum in the high acetonitrile content region is observed in the case of the MeOH–ACN mixture. A possible explanation of this behaviour is discussed. Enthalpic pair interaction coefficients for the systems under study have been calculated and analysed.

Single-ion transfer enthalpies in methanol-acetonitrile mixtures at 298.15 K based on the Ph4P+ = BPh4− assumption

Abstract The enthalpies of solution of KI, NaBPh4 and Ph4PI in methanol-acetonitrile mixtures were measured at 298.15 K. From these data, together with those for NaI taken from our earlier work, and with literature data that refer to (n-Bu)4NBr, (n-Bu)4NI and (n-Bu)4ClO4, the enthalpies of transfer of the individual ions Ph4P+, BPh−4, Na+, K+, Br−, I−, ClO4− and (n-Bu)4N+ from methanol to acetonitrile-methanol mixtures were calculated employing the assumption ΔHtXXX(Ph4P+) = ΔHtXXX(BPh−4).

Single-ion transfer enthalpies for Ph4P+ = BPh−4 Na+ and I− ions in methanol-N,N-dimethylformamide mixtures

Abstract Enthalpies of solution of Ph 4 PI and NaBPh 4 in rnethanol- N,N -dimethylformamide (DMF) mixtures have been measured within the whole range of the mixed solvent composition. The ionic contribution to the transfer enthalpy from methanol to methanol-DMF mixtures based on the assumption that Δ H t XXX (BPh − 4 ) = Δ H t xxx (Ph 4 P + ), has been calculated using the data obtained and earlier data for NaI solution. The single-ion transfer enthalpies change monotonically with the mixtures composition, without any extrema typical of the systems containing water as a component of the mixed solvent.

Conductivity study of NaI solutions in n-propanol–n-butanol mixtures at 298.15 K

The electrical conductivity of NaI solutions in binary n-propanol–n-butanol mixtures within the whole composition range has been measured and analysed using the Fuoss–Justice equation. With increasing n-butanol content the limiting molar conductance decreased and the equilibrium constant of ion-pair formation increased. The standard dissolution enthalpies of NaI in the same binary mixtures (published earlier) have been recalculated taking into account the ion-association process.

Ion solvation in methanol—organic cosolvent mixtures Part 5. Enthalpies of transfer of inorganic ions in mixtures of methanol and propylene carbonate at 298.15 K☆

Abstract The enthalpies of solution of NaBr, NaI and NaClO4 in methanol + propylene carbonate mixtures were measured at 298.15 K. From these data, together with literature data that refer to (n-Bu)4NBr, (n-Bu)4NB(n-Bu)4 and (n-Bu)4NClO4 the enthalpies of transfer of the individual ions Na+, Br−, I−, ClO−4 and (n-Bu)4N+, from methanol to methanol + propylene carbonate mixtures were calculated employing the assumption ΔtrH∞(n-Bu)4N+ = ΔtrH∞B(n-Bu)−4. The dependences of the single-ion transfer enthalpies on the mixed solvent composition are discussed.

Single Ionic Volumes in Acetonitrile–Organic Cosolvent Mixtures at 298.15 K

Abstract Densities of binary nonaqueous mixtures of acetonitrile (AN) with 2-methoxyethanol (ME), N,N-dimethylacetamide (DMA) and propylene carbonate (PC) were determined over the whole composition range at 298.15 K. The excess molar volumes and the partial molar volumes of both components were calculated from these data. Densities of solutions of NaI, NaBPh4 and Ph4PI in solvent mixtures AN + ME and AN + DMA and of NaI solutions in mixtures of AN + PC were measured over the whole composition range of the mixed solvents at an electrolyte concentration equal 0.05 mol dm−3. From these densities, apparent molar volumes of electrolytes and ions were evaluated and analyzed. The relationship between the apparent molar volumes of ions and (κT/ε) parameter was tested and discussed.

Calorimetric investigation of NaI-alcohol interactions in alcohol+alcohol mixtures

Enthalpies of solution of sodium iodide in mixtures of methanol with ethanol, n-propyl alcohol and isopropyl alcohol have been measured at 298.15 K over the entire range of mixture compositions. Standard solution enthalpies exhibit maxima in the region of high n-propyl alcohol and isopropyl alcohol contents in the system, while in the case of the methanol + ethanol system the standard enthalpy has a monotonic character. Enthalpic NaI–alcohol pair-interaction coefficients for the systems under study have been calculated and analysed.

Calorimetric Investigations of Complex Formation of 2,3,4,5,6-Pentafluoroaniline with Proton Acceptors in CCl4

Abstract Solution enthalpies of 2,3,4,5,6-pentafluoraniline in CCl4 as well as in the solutions of tetrahydrofuran and hexamethylphosphoric triamide have been measured. From the obtained data and spectroscopically determined equilibrium constants the enthalpies of the complex formation of 2,3,4,5,6-pentafluoroaniline with one and two molecules of tetrahydrofuran and hexamethylphosphoric triamide have been calculated. The results yielded from the combination of calorimetric and spectroscopic data have been compared with those obtained using the i.r. method only.

Thermochemical investigations of the systems useful for lithium battery construction: Part 2. Solution enthalpies of LiClO4 in 1,2-dimethoxyethane + γ-butyrolactone mixtures and of LiClO4, NaI and N,N-dimethylacetamide in 1,2-dimethoxyethane + propylene carbonate mixtures at 298.15 K☆

Abstract Solution enthalpies of LiClO 4 in 1,2-dimethoxyethane + γ-butyrolactone (1,2-DME + γBL) mixtures and of LiClO 4 , NaI and N,N-dimethylacetamide in 1,2-DME + propylene carbonate (PC) mixtures have been measured. The molar enthalpies of solution, Δ sol H m of the examined electrolytes as a function of the mixed solvent composition exhibit a distinct minimum within the range of high 1,2-DME content, similar to those observed earlier for LiBF 4 and LiPF 6 solutions in 1,2-DME + γ-BL mixtures while the dissolution enthalpy of DMA runs monotonously within the same range of the mixed solvent compositions. The presence of the Δ sol H m minimum of the salts is explained as a resultant of energetic effects of interactions in the solution, connected with the ionic association of the salt, the 1,2-DME + cation complex formation and changes in a composition of the ionic solvation shells