Hydrogen bonding Original Scenario-Based Download PDF

Questions

1. 1.

   A deep-space habitat synthesizes four volatile analogs of comparable molar mass to formulate an emergency coolant that relies on an unusually elevated boiling point and high liquid cohesion. Among the candidate liquids, the automated synthesizer tests pure samples of fluoromethane ($CH_3F$), methanethiol ($CH_3SH$), dimethyl ether ($CH_3OCH_3$), and ethanol ($CH_3CH_2OH$). Which of these compounds participates in intermolecular hydrogen bonding in its pure liquid phase to produce the highest boiling point?

   • A) Fluoromethane ($CH_3F$), because the strongly electronegative fluorine atom polarizes the adjacent carbon-hydrogen bonds.
   • B) Methanethiol ($CH_3SH$), because the polar thiol group contains a hydrogen atom directly bonded to sulfur.
   • C) Dimethyl ether ($CH_3OCH_3$), because the central oxygen atom with lone pairs coordinates with terminal methyl hydrogen atoms.
   • D) Ethanol ($CH_3CH_2OH$), because a hydrogen atom covalently bonded to a highly electronegative oxygen atom interacts with lone pairs on adjacent molecules.