A Volumetric Study of Aqueous Butanol Solutions

• Main Author: Chary, Priyanka P
• Format: Others
• Published: Scholarship @ Claremont 2014
• Subjects: Chemistry
• Online Access: http://scholarship.claremont.edu/scripps_theses/319; http://scholarship.claremont.edu/cgi/viewcontent.cgi?article=1332&context=scripps_theses

Alcohol molecules consist of two distinct regions: a polar, hydrophilic alcohol group, and an aliphatic hydrocarbon chain. These regions interact with solvent water molecules in different ways. While the alcohol group acts as a solvent structure breaker by hydrogen bonding with nearby water molecules, the hydrophobic carbon chain acts instead as a solvent structure maker and causes the surrounding water molecules to align themselves in a Clathrate structure. The presence of these two contrasting solute-solvent interactions affects the properties of the solution, among them the molar volume. The partial molar volume of the alcohol is analyzed with respect to three variables: the size and location of the hydrophilic moiety, the concentration of the alcohol-water solution, and the temperature at which the density measurement is made. We show that all three of these variables have a noticeable effect on the interactions between the solute and solvent molecules, and thus the volume of the solution.