Final answer:
A hydrogen bond will not form between the oxygen atom and hydrogen atom indicated due to incorrect molecular geometry, which prevents the close proximity required for a hydrogen bond to occur.
Step-by-step explanation:
The question at hand is why a hydrogen bond will not form between the oxygen atom and hydrogen atom as indicated by the red dashed line. Hydrogen bonds are a type of dipole-dipole interaction that happens when a hydrogen atom, which is covalently bonded to a highly electronegative atom like oxygen, nitrogen, or fluorine (hydrogen bond donor), associates with a lone pair of electrons on a neighboring electronegative atom (hydrogen bond acceptor).
The likely reason a hydrogen bond will not form in the scenario described is due to incorrect molecular geometry; the spatial arrangement of the atoms might not allow for the close proximity necessary for a hydrogen bond to occur. Options such as unequal electronegativity, excessive molecular weight, and presence of lone pairs do not typically impede the formation of hydrogen bonds in cases where the molecular geometry is appropriate for such interactions.