Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Influence of aliphatic amides on the temperature of maximum density of water

Torres, A. F.[Andres Felipe], Romero, C. M.[Carmen M.]
J. Chem. Thermodyn. 2017, 105, 173-178
ABSTRACT
The influence of dissolved substances on the temperature of the maximum density of water has been studied in relation to their effect on water structure as they can change the equilibrium between structured and unstructured species of water. However, most work has been performed using salts and the studies with small organic solutes such as amides are scarce. In this work, the effect of acetamide, propionamide and butyramide on the temperature of maximum density of water was determined from density measurements using a magnetic float densimeter. Densities of aqueous solutions were measured within the temperature range from T = (275.65-278.65) K at intervals of 0.50 K in the concentration range between (0.10000 and 0.80000) mol kg-1. The temperature of maximum density was determined from the experimental results. The effect of the three amides is to decrease the temperature of maximum density of water and the change does not follow the Despretz equation. The results are discussed in terms of solute-water interactions and the disrupting effect of amides on water structure.
Compounds
# Formula Name
1 C2H5NO ethanamide
2 C3H7NO propanamide
3 C4H9NO butanamide
4 H2O water
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • 4
  • Mass density, kg/m3 ; Liquid
  • Temperature, K; Liquid
  • Molality, mol/kg - 1; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Buoyancy - hydrostatic balance with magnetic suspension - one sinker
  • 56
  • POMD
  • 2
  • 4
  • Mass density, kg/m3 ; Liquid
  • Temperature, K; Liquid
  • Molality, mol/kg - 2; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Buoyancy - hydrostatic balance with magnetic suspension - one sinker
  • 56
  • POMD
  • 3
  • 4
  • Mass density, kg/m3 ; Liquid
  • Temperature, K; Liquid
  • Molality, mol/kg - 3; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Buoyancy - hydrostatic balance with magnetic suspension - one sinker
  • 56