Abstract
Vapour pressures of water over saturated solutions of l-ascorbic acid and calcium-l-ascorbate were measured in the 280 K to 318 K temperature range and the activities of water, osmotic coefficients and the molar enthalpies of vaporization were derived from them. Densities of aqueous solutions of l-ascorbic acid, magnesium-l-ascorbate and calcium-l-ascorbate were determined at 5 K temperature intervals, from T = 288.15 K to T = 333.15 K. Densities served to evaluate the apparent molar volumes, V2,φ{symbol}(m,T), the cubic expansion coefficients, α(m,T) and the changes of isobaric heat capacities with respect to pressure, (∂CP / ∂P)T,m. They were qualitatively correlated with the changes in the structure of water when ascorbic acid and magnesium and calcium ascorbates are dissolved in it.
Original language | English |
---|---|
Pages (from-to) | 7-16 |
Number of pages | 10 |
Journal | Journal of Molecular Liquids |
Volume | 131-132 |
Issue number | SPEC. ISS. |
DOIs | |
State | Published - 15 Mar 2007 |
Keywords
- Apparent molar volumes
- Aqueous saturated solutions
- Calcium-l-ascorbate
- Densities
- Magnesium-l-ascorbate
- Thermal expansibilities
- Vapour pressures
- Water activities
- l-ascorbic acid
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Spectroscopy
- Physical and Theoretical Chemistry
- Materials Chemistry