SUPERCOOLING AND ENTHALPY OF MIXING OF AQUEOUS-SOLUTIONS OF TETRABUTYLAMMONIUM (OR ISOPENTYLAMMONIUM) CHLORIDE SUBJECTED TO DIFFERENT THERMAL TREATMENTS
Nakayama, H; Hayashi, C
| HERO ID | 1195276 |
|---|---|
| In Press | No |
| Year | 1995 |
| Title | SUPERCOOLING AND ENTHALPY OF MIXING OF AQUEOUS-SOLUTIONS OF TETRABUTYLAMMONIUM (OR ISOPENTYLAMMONIUM) CHLORIDE SUBJECTED TO DIFFERENT THERMAL TREATMENTS |
| Authors | Nakayama, H; Hayashi, C |
| Journal | Thermochimica Acta |
| Volume | 253 |
| Page Numbers | 77-84 |
| Abstract | In order to observe more directly the structural organization of water molecules around an apolar molecule in an aqueous solution, supercooling phenomena and enthalpies of mixing with various solvents have been examined using aqueous solutions of tetrabutylammonium (or isopentylammonium) chloride subjected to different thermal treatments. Solution I was kept at a temperature only one degree higher than its dissolution temperature, at which a hydrate crystal phase was completely dissolved. The temperature of solution II was raised to 80 degrees C. The supercooling temperatures of solution I were found to be rather higher than those of solution II: 10-15 degrees C for (n-C4H9)(4)NCl and about 20 degrees C for (i-C5H11)(4)NCl, regardless of the concentrations of these salts. The differences of the enthalpies of mixing between solution I and solution II in the same solvent Delta H-I - Delta H-II were determined. It was found that, (1) for solvents such as acetone, tetrahydrofuran, and 1, 4-dioxane, Delta H-I - Delta H-II values were about 10 kJ per mole of (n-C4H9)(4)NCl which contained 49 moles of water (i.e. the mole fraction of a sample solution was 0.02), and (2) when the solvents were alcohols (methanol and ethanol), the Delta H-I - Delta H-II value became rather small and in the case of water the Delta H-I - Delta H-II value became even smaller (1.1 kJ mol(-1)). It is concluded that the difference in the stability of water networks between solutions I and II is 0.204 kJ per mole of water, which corresponds to about 3.4% of the enthalpy of fusion of ice I.< |
| Doi | 10.1016/0040-6031(94)02017-I |
| Wosid | WOS:A1995QX84400010 |
| Is Certified Translation | No |
| Dupe Override | No |
| Comments | Source: Web of Science A1995QX84400010 |
| Is Public | Yes |
| Keyword | HEAT OF MIXING; ISOPENTYLAMMONIUM CHLORIDE; PHASE DIAGRAM; SLE; SUPERCOOLING; TETRABUTYLAMMONIUM CHLORIDE |
| Is Qa | No |