[neobenzene]

Hi! I have this major, basic doubt. Is intermolecular hydrogen bonding strong or weak? I have always been taught in school that they are "strong" bonds, but I came across this video on YouTube recently which states that they are "weak" bonds.

Which one is right?

[discodermolide]

Hi! I have this major, basic doubt. Is intermolecular hydrogen bonding strong or weak? I have always been taught in school that they are "strong" bonds, but I came across this video on YouTube recently which states that they are "weak" bonds.

Which one is right?

A quote from a Wiki page:
"The hydrogen bond (5 to 30 kJ/mole) is stronger than a van der Waals interaction, but weaker than covalent or ionic bonds. This type of bond occurs in both inorganic molecules such as water and organic molecules like DNA."

[neobenzene]

But are hydrogen bonds strong enough to raise the melting/boiling points of a molecule?

[DrCMS]

Yes and water is the classic example.

[neobenzene]

So does that mean, NaI, which is very covalent according to Fajan's rule, has very high melting/boiling points? And by this, theoretically it should be more than that of water. Is that right?

[discodermolide]

So does that mean, NaI, which is very covalent according to Fajan's rule, has very high melting/boiling points? And by this, theoretically it should be more than that of water. Is that right?

Yes it has a much much higher MPt. and BPt. than water, and not just theoretically.

[neobenzene]

Thank you very much, discodermolide and DrCMS!