278.15～318.15 K下葡萄糖在盐酸中的体积性质

测定了278.15～318.15 K(间隔10 K)下葡萄糖＋HCl＋水三元体系的密度, 计算了葡萄糖在盐酸(浓度0.2～2.1 mol•kg^–1)中的表观摩尔体积V_Φ,G、标准偏摩尔体积V⁰_Φ,G、葡萄糖-HCl在水中的体积对相互作用参数V_EG和标准偏摩尔膨胀系数(∂V⁰_Φ,G/∂T)_p. 结果表明: (1)葡萄糖在盐酸中的表观摩尔体积随葡萄糖和HCl的浓度的增加而线性增大; (2) V⁰_Φ,G随HCl的质量摩尔浓度的增加而线性增大; (3)葡萄糖与HCl在水溶液中的体积相互作用参数V_EG＞0, 但数值对温度变化不甚敏感; (4)葡萄糖在水和盐酸中的V⁰_Φ,G值随实验温度的变化关系均可表示为: V⁰_Φ,G＝a₀＋a₁(T－273.15 K) ^2/3; (5) (∂V⁰_Φ,G/∂T)_p为正值且随温度的升高而减小; 在一定温度下, 其值随HCl浓度的增加而稍稍减小. 糖的水化程度随温度的升高和HCl的浓度的增加而减小. 用结构相互作用模型对葡萄糖与HCl之间的体积相互作用进行了解释.

Volumetric Properties of Glucose in Aqueous HCl Solutions at Tem-peratures from 278.15 to 318.15 K

Densities have been measured for glucose＋HCl＋water at 10 K intervals from 278.15 to 318.15 K. The apparent molar volumes (V_Φ,G), standard partial molar volumes (V⁰_Φ,G) for glucose in aqueous solution of 0.2, 0.4, 0.7, 1.1, 1.6, 2.1 mol•kg^－1 HCl have been calculated as well as volumetric interaction parameters (V_EG) for glucose-HCl in water and standard partial molar expansion coeffi-cients(∂V⁰_Φ,G/∂T)_p. Results show that (1) the apparent molar volumes for glucose in aqueous HCl solutions increases lineally with increasing molality of glucose and HCl; (2) V⁰_Φ,G for glucose in aqueous HCl solutions in-creases lineally with increasing molality of HCl; (3) the volumetric interaction parameters for glucose-HCl pair in water are small positive and vary slightly with temperature; (4) the relation between V⁰_Φ,G and temperature exists as V⁰_Φ,G＝a₀＋a₁(T－273.15 K) ^2/3; (5) values of (∂V⁰_Φ,G/∂T)_p are positive and increase as temperatures rise, and at given temperatures decrease slightly with increasing molalities of HCl, indicating that the hydration of glucose decreases with increasing temperature and molality of HCl. These phenomena are interpreted successfully by the structure interaction model.