Apparent and Standard Partial Molar Volumes of NaCl, NaOH, and HCl in Water and Heavy Water at T = 523 K and 573 K at p = 14 MPa
详细信息 查看全文
- 作者：Liliana N. Trevani ; Erik C. Balodis ; Peter R. Tremaine
- 刊名：Journal of Physical Chemistry B
- 出版年：2007
- 出版时间：March 1, 2007
- 年：2007
- 卷：111
- 期：8
- 页码：2015 - 2024
- 全文大小：145K
- 年卷期：v.111,no.8(March 1, 2007)
- ISSN：1520-5207
文摘
Apparent molar volumes, V
,2, of aqueous NaCl, NaOH, NaOD, HCl, and DCl in water and heavy waterwere determined at T = 523 and 573 K and p = 14 MPa with a high-temperature platinum vibrating-tubedensimeter in the aquamolality range 0.25 
maq 2.5 mol· (55.509 mol solvent)-1. The experimental resultshave been represented with an extended Debye-Hückel equation to describe the concentration dependenceof V,2 and to derive standard partial molar volumes of these electrolytes in light and heavy water, V
2,H andV2,D, respectively. For NaCl and NaOH, the D2O isotope effect at infinite dilution, [V2,H - V2,D], increasesfrom 0.2 and 0.8 cm3 mol-1 to 4.5 and 7.1 cm3 mol-1, respectively, when the temperature is increased from523 to 573 K. For HCl and DCl, the effect is smaller and the sign is reversed, [V2,H - V2,D] = -0.7 cm3mol-1 at 523 K and -1.4 cm3 mol-1 at 573 K. When the effect of ion association is included, the deuteriumisotope effect for HCl becomes positive, [V2,H - V2,D] 
17 cm3 mol-1 at 573 K, consistent with NaCl andNaOH. Two models are proposed to describe the solvent isotope effect on the infinite dilution limit, onebased on the Born equation and the other on the dimensionless Krichevskii parameter. The experimentalvalues of V2,D also have been used to calculate the first reported values for the pressure dependence of theionization constant of D2O at temperatures higher than 313 K.
,2, of aqueous NaCl, NaOH, NaOD, HCl, and DCl in water and heavy waterwere determined at T = 523 and 573 K and p = 14 MPa with a high-temperature platinum vibrating-tubedensimeter in the aquamolality range 0.25 maq 2.5 mol· (55.509 mol solvent)-1. The experimental resultshave been represented with an extended Debye-Hückel equation to describe the concentration dependenceof V,2 and to derive standard partial molar volumes of these electrolytes in light and heavy water, V2,H andV2,D, respectively. For NaCl and NaOH, the D2O isotope effect at infinite dilution, [V2,H - V2,D], increasesfrom 0.2 and 0.8 cm3 mol-1 to 4.5 and 7.1 cm3 mol-1, respectively, when the temperature is increased from523 to 573 K. For HCl and DCl, the effect is smaller and the sign is reversed, [V2,H - V2,D] = -0.7 cm3mol-1 at 523 K and -1.4 cm3 mol-1 at 573 K. When the effect of ion association is included, the deuteriumisotope effect for HCl becomes positive, [V2,H - V2,D] 17 cm3 mol-1 at 573 K, consistent with NaCl andNaOH. Two models are proposed to describe the solvent isotope effect on the infinite dilution limit, onebased on the Born equation and the other on the dimensionless Krichevskii parameter. The experimentalvalues of V2,D also have been used to calculate the first reported values for the pressure dependence of theionization constant of D2O at temperatures higher than 313 K.