Methyl acetate can form hydrogen bonds with water but not with itself because of the nature of its molecular structure and hydrogen bonding requirements:
- Hydrogen bonding requires a hydrogen atom attached to a highly electronegative atom (such as oxygen, nitrogen, or fluorine) to create a significant partial positive charge on hydrogen and a lone pair on another electronegative atom to accept the hydrogen bond
- In methyl acetate, the oxygen atoms (particularly the carbonyl oxygen) have lone pairs that can act as hydrogen bond acceptors, but the hydrogens in methyl acetate are attached to carbon atoms, which are not sufficiently electronegative to produce the partial positive charge necessary for donating hydrogen bonds
- Therefore, methyl acetate molecules cannot form hydrogen bonds with each other because they lack hydrogen atoms bonded to electronegative atoms (like O-H or N-H) that can donate hydrogen bonds.
- However, water molecules have hydrogens bonded to oxygen, making them good hydrogen bond donors. These hydrogens can form hydrogen bonds with the lone pairs on the oxygen atoms of methyl acetate, allowing methyl acetate to hydrogen bond with water molecules
In summary, methyl acetate can accept hydrogen bonds from water (which can donate them) but cannot donate hydrogen bonds itself, so it does not form hydrogen bonds with other methyl acetate molecules. This explains why methyl acetate forms hydrogen bonds with water but not with itself.
