CHEM1101 question. (1 Viewer)

[nml10]

Which of H20, CH3Cl, H2S and O2 would you expect to form strong hydrogen bonds?

a) H2O only
b) H2O and H2S only
c) H2O and O2 only
d) H2O, CH3Cl and H2S only
e) all of them

The answer is a) and it is what I chose when I made the attempt. But my question is, is it always the case? Is H2O ALWAYS expected to form strong hydrogen bonds with other molecules?

 

[nightweaver066]

I don't do university chemistry, but maybe it's because of the two very electronegative oxygens attached to the hydrogen?

Induces quite strong partial charges allowing for 'strong' hydrogen bonds with other molecules.

Maybe it's not expected but it's just a property of water.

 

[nml10]

Ooh, genius!

But if I am asked a question regarding the strength of the hydrogen bond, would I expect H2O to be the strongest?

 

[nightweaver066]

Ooh, genius!

But if I am asked a question regarding the strength of the hydrogen bond, would I expect H2O to be the strongest?

Probably not. Fluorine is even more electronegative than oxygen, so a H-F bond will result in even stronger partial charges (in fact, the strongest as it is the most electronegative element).

 

[UncoKane]

The hydrogens on the water molecule are hydrogen bond donators and N, O or F can accept the hydrogen bond due to their lone pairs. H2O won't form H bonds with EVERY other molecule. Only ones which can accept the hydrogen bond, i.e. ones that contain N, O or F. The O can also accept other hydrogen bonds and so would form strong hydrogen bonds with other water molecules. H2S and CH3Cl don't fit this and O2 has no hydrogens with which to donate the hydrogen bond.