Masao Tsuchiya

Effect of pressure on the solubilities of LiF, NaF, KCl, NH4, Cl, K2SO4, (NH4)2SO4, and ZnSO4·7H2O in water at 298.15 K

Abstract Solubilities of seven inorganic compounds in water were measured at 298.15 K and up to 350 MPa. The solubilities of K2SO4, LiF, NaF, and KCI increased with increasing pressure, those of NH4Cl and (NH4)2SO4 decreased, and that of ZnSO4·7H2O showed almost no dependence on pressure. From the slopes of these solubility curves at 0.1 MPa, we estimated the volume changes accompanying the dissolution of the solutes. These values coincided with the volume differences between the partial molar volume at saturation and the molar volume of the crystal within ca. ± 1 cm3 mol−.

Effect of Pressure on the Hydrogen-Bond Formation between Phenol as a Proton Donor and Three Ethers in N-hexane

Abstract The effect of pressure on the hydrogen (H)-bond formation between phenol as a proton donor and three simple aliphatic ethers as proton acceptors in n -hexane was studied by means of UV absorption spectroscopy up to 640 MPa at 25°C. The reaction volumes for H-bond formation were -6.1 cm 3 mol −1 for diethyl-, -6.4 cm 3 mol −1 for di- n -propyl-, and -5.1 cm 3 mol −1 for di- n -butyl ether, respectively. They show that the reaction volume for H-bond formation between phenol and aliphatic ether is about -6 cm 3 mol −1 without depending on the length of the substituents of a proton donor.

Some Physicochemical Properties of Water and Aqueous Solutions under High Pressure — Hydrophobic Hydration

It is well recognized from the analysis of x-ray diffraction that liquid water at atmospheric pressure retains the four-coordinated open structure of ice-I. On the other hand, the critical pressure for the presence of ice-I is well known to be about 2 kbars in the phase diagram of water. These two facts suggest the possibility that compressed liquid water might retain the structure of dense ice of the corresponding high-pressure phase, and that the physicochemical properties of liquid water are changed dramatically above about 2 kbars.