Related Experiment Videos
Relationship between cohesive energy density and hydrophobicity
1Dipartimento di Scienze Biologiche ed Ambientali, Universita del Sannio, Via Port'Arsa, 11-82100 Benevento, Italy. graziano@unisannio.it
The Journal of Chemical Physics
|July 21, 2004
Summary
The cohesive energy density of water does not solely explain hydrophobicity. Nonpolar compounds show slightly higher solubility in heavy water (D2O) than light water (H2O), challenging this theory.
Area of Science:
- Physical Chemistry
- Solution Chemistry
Background:
- The cohesive energy density of water has been proposed as the primary reason for the poor solubility of nonpolar compounds.
- Hydrophobicity is a critical factor in various chemical and biological processes.
Purpose of the Study:
- To investigate the role of cohesive energy density in the solubility of nonpolar compounds.
- To compare the solvent properties of light water (H2O) and heavy water (D2O) for nonpolar solutes.
Main Methods:
- Comparative analysis of nonpolar compound solubility in H2O and D2O.
- Evaluation of cohesive energy density and void volume differences between H2O and D2O.
Main Results:
- Nonpolar compounds exhibited slightly greater solubility in D2O compared to H2O.
- Despite D2O having a higher cohesive energy density, solubility was enhanced.
- The experimental data do not support cohesive energy density as the sole cause of hydrophobicity.
Conclusions:
- The large cohesive energy density of water is not the ultimate cause of hydrophobicity.
- D2O is a slightly better solvent for nonpolar compounds due to a less costly cavity formation, attributed to greater void volume.