What accounts for the higher boiling point of NH3? At standard pressure, NH3 has a boiling point of 240 K, AsH3 has a boiling point of 211 K, and PH3 has a boiling point of 186 K.

NH₃ has a higher boiling point, because it contains hydrogen bonds.

Nonpolar Molecules (Symmetrical distribution of charge)=London Dispersion (weakest); Polar Molecules (Asymmetrical distribution of charge)=Dipole-Dipole Forces; Molecules with H-F, H-O, or H-N (because of big EN)=Hydrogen Bonding; Saltwater (ionic compound and water)=Ion-Dipole Forces (strongest). NH3 has H-N, so it has hydrogen bonding. AsH3 and PH3 are polar molecules (asymmetrical distribution of charge) without H-O, N-H, and H-F, so they have dipole-dipole forces. Hydrogen bonding is stronger than dipole-dipole forces are, so NH3 has the highest boiling point, because it has the strongest IMFs out of the three molecules.*##**##*