The increasing order of boiling points for the following compound is:
A. C2H5OH
B. C2H5Cl
C. C2H5CH3
D. C2H5OCH3

• A. C₂H₅OH (Ethanol) - Highest Boiling Point
  • Force:Hydrogen Bonding. The presence of the -OH group allows ethanol molecules to form strong hydrogen bonds with each other, which are the strongest type of IMF in this list.
• B. C₂H₅Cl (Chloroethane) - Second Highest
  • Force:Dipole-Dipole Interactions. The chlorine atom is more electronegative than carbon, making the molecule polar. These polar molecules attract each other. It has a higher boiling point than methoxyethane due to its greater molar mass and stronger dipole moment.
• D. C₂H₅OCH₃ (Methoxyethane) - Third Highest
  • Force:Dipole-Dipole Interactions. The oxygen atom makes the ether molecule polar. However, it cannot form hydrogen bonds with itself, and its dipole-dipole forces are weaker than those in chloroethane.
• C. C₂H₅CH₃ (Propane) - Lowest Boiling Point
  • Force:Van der Waals Forces. Propane is a nonpolar alkane. The only forces holding its molecules together are the very weak London dispersion forces (a type of van der Waals force).

Therefore, the correct order from lowest to highest boiling point is: Propane < Methoxyethane < Chloroethane < Ethanol