If a solid line represents a covalent bond & a dotted line represents intermolecular attraction which of these choices shows a hydrogen bond?

h3n……H–o–h

This is the only one:

h3n……H–o–h

The H in the H-bond has to be connected to N, O, or F and it H-bonds to only N, O, F on the other side,

h20…..h–ch3 <--- the H is connected to a C. No H-bonding. H must be connected to N, O, F. h4c.....h---f <--- the H is shown H-bonded to a C. this is incorrect. It must H-bond to N, O, F.

Hydrogen bonds are intermolecular forces where a hydrogen bonds to an oxygen, fluorine, or nitrogen. All of them show hydrogen bonding except h–h and h4c…..h—-f.