Potassium bromide (KBr) is an ionic solid commonly used in infrared spectroscopy as a…
CHEMISTRY · Multi-part · AP · Chemistry · Properties of Substances and Mixtures · Properties of Substances and Mixtures
Problem
Potassium bromide (KBr) is an ionic solid commonly used in infrared spectroscopy as a transparent matrix. A laboratory technician must choose a solvent to dissolve trace amounts of KBr for a cleaning procedure. Three candidate solvents are available at 25 °C and 1 atm:
• Water (H2O)
• Methanol (CH3OH)
• n-Hexane (C6H14)
Respond to the prompts below.
(a) Rank the three solvents from most effective to least effective for dissolving KBr.
(b) For the solvent you ranked as most effective, write a detailed explanation of the specific intermolecular interactions that would occur between the solvent molecules and the ions in KBr as the solid dissolves.
(c) For the solvent you ranked as least effective, provide one molecular-level reason for its poor performance in dissolving KBr.