| Popis: |
Specific heat capacities, apparent molar heat capacities, densities, and apparent molar volumes were determined for aqueous glucose at temperatures from 298.15 K to 327.01 K. The molalities investigated ranged from 0.20 mol·kg-1 to 1.54 mol·kg-1. The results of these measurements have been used to calculate the following thermodynamic quantities for {C6H12O6 (glucose)}(aq) at T = 298.15 K: Cop, φ, 2 = Cop, 2, m = (345±4) J·K-1·mol-1; (∂Cop, 2, m/∂T)p = (1.45±0.22) J·K-1·mol-1; (∂2Cop, 2, m/∂T2)p = (0.053±0.015) J·K-3·mol-1; Voφ, 2 = Vo2, m = (111.99±0.10) cm3·mol-1; (∂Vo2, m/∂T)p = (0.084±0.032) cm3·K-1·mol-1; and (∂2Vo2, m/∂T2)p = -(8.9±2.2)·10-3 cm3·K-2·mol-1. The first virial coefficient in the expression for the excess molar volume is (0.470±0.022) cm3·kg·mol-2. For the reaction α-l-glucose(aq) = β-l-glucose(aq), ΔrCop, m = (2±2) J·K-1·mol-1 and ΔrVom = (0.59±0.05) cm3·mol-1. These results are compared with the results from the literature. A discussion of systematic errors attributable to instrument errors, sample impurities, and incomplete anomeric and relaxation equilibrium in the solutions is given. |
