Question

Which substance has the strongest hydrogen bond and why

Answer 1

Answer:

The strength of an individual H bond depends on the polarity of the H-X bond and therefore on the electronegativity of X ( the more delta positive the H atom, the stronger the electrostatic force of attraction between it and a lone pair of electrons). Thus, on a per bond basis, HF H bonding is strongest. However, as water has two H atoms, each molecule can form two H bonds so on a per molecule basis, water H bonding is strongest (this is evidenced by the boiling points of the three substances; NH3 < HF < H2O.)

Answer 2

On the basis of bond, HF H bonding is strongest. However, as water has two H atoms, each molecule can form two H bonds so on a per molecule basis, water H bonding is strongest (this is evidenced by the boiling points of the three substances; NH3 < HF < H2O.)