Question

Which has the highest boiling point?
O He
O H₂
O Cl₂
O CH4
O HF

Answer 1

HF (hydrogen fluoride)

Step-by-step explanation:

HF exhibits strong hydrogen bonding, which significantly raises its boiling point compared to the other molecules:

He (helium): A noble gas with very weak intermolecular forces, so it has a very low boiling point.

Hydrogen bond

H₂ (hydrogen): A nonpolar molecule with only London dispersion forces, resulting in a low boiling point.

Cl₂ (chlorine): A nonpolar molecule with London dispersion forces, but weaker than HF’s hydrogen bonding.

Methane

CH₄ (methane): A nonpolar molecule with only London dispersion forces, so it has a relatively low boiling point.

HF (hydrogen fluoride): Exhibits strong hydrogen bonding due to the electronegativity difference between hydrogen and fluorine, resulting in a higher boiling point.