In flushing and cleaning columns used in liquid chromatography to remove adsorbed contaminants, a series of solvents is used. Hexane \(\left(\mathrm{C}_{6} \mathrm{H}_{14}\right),\) chloroform \(\left(\mathrm{CHCl}_{3}\right),\) methanol \(\left(\mathrm{CH}_{3} \mathrm{OH}\right),\) and water are passed through the column in that order. Rationalize the order in terms of intermolecular forces and the mutual solubility (miscibility) of the solvents.

First, we need to identify the intermolecular forces (IMF) present in each solvent. Intermolecular forces are the forces that hold molecules together and determine their physical properties. 1. Hexane: As a non-polar hydrocarbon, the primary IMF in hexane is London dispersion forces. 2. Chloroform: Being a polar molecule with a dipole moment, chloroform experiences both dipole-dipole interactions and London dispersion forces. 3. Methanol: As a polar molecule with a hydroxyl group, methanol displays hydrogen bonding, dipole-dipole interactions, and London dispersion forces. 4. Water: Water is also a polar molecule with hydroxyl groups. Like methanol, it experiences hydrogen bonding, dipole-dipole interactions, and London dispersion forces.

Next, we will assess the miscibility of these solvents with each other and rationalize the given order based on their intermolecular forces and solubilities. 1. Hexane is passed through the column first because it is non-polar and can dissolve other non-polar contaminants best owing to its London dispersion forces. Moreover, hexane is immiscible with water. 2. Chloroform is passed after hexane because it is less polar than methanol and water but more polar than hexane. Therefore, it can dissolve some polar contaminants due to its dipole-dipole interactions. Mixing with hexane is also favorable because of the relatively similar strength of intermolecular forces in both solvents. 3. Methanol comes next in the order. As a polar solvent with hydrogen bonding capabilities, it can dissolve polar contaminants even further than chloroform. Methanol is miscible with chloroform due to the presence of dipole-dipole interactions. 4. Finally, water is passed through the column as the most polar solvent. Its strong hydrogen bonding capacity can dissolve polar contaminants that methanol might not have removed. Water is miscible with methanol due to the hydrogen bonding capabilities in both solvents. In conclusion, the solvents are ordered based on their increasing polarity and strength of intermolecular forces, which allows efficient removal of contaminants in a gradual and controlled manner during the column flushing process in liquid chromatography.