A pharmacy student must prepare a homogeneous solution of the over-the-counter…
CHEMISTRY · Multi-part · AP · Chemistry · Properties of Substances and Mixtures · Properties of Substances and Mixtures
Problem
A pharmacy student must prepare a homogeneous solution of the over-the-counter analgesic ibuprofen for an analytical assay. A supply cabinet offers the following solvents of analytical grade purity:
• Hexane
• Ethanol (95 %)
• Deionized water
• Dichloromethane (DCM)
Ibuprofen is a solid at room temperature containing a carboxylic acid functional group attached to a largely hydrophobic aromatic-alkyl framework.
Respond to the tasks below.
(a) Select the single solvent from the list that will dissolve the greatest mass of ibuprofen at 25 °C. State the solvent by name only.
(b) Provide a detailed explanation, referencing polarity and specific intermolecular forces, that accounts for the superior solubility of ibuprofen in the solvent chosen in part (a).
(c) Describe qualitatively how increasing the temperature from 25 °C to 40 °C is expected to influence the solubility of ibuprofen in the chosen solvent, and support your prediction with thermodynamic reasoning.