[SOLVED] Hydrogen bonding Which types of bonding are present in CH3CHO(=ethanal) in the liquid state? I. Single covalent bonding II. Double covalent bonding III. Hydrogen bonding A. I and II only B. I and III only C. II and III only D. I, II and III The solution is A but I can not understand why it is not D. Namely, why would there be no hydrogen bonding in ethanal? I think there is no intramolecular hydrogen bonding but there should be intermolecular hydrogen bonding. Can someone explain why A is correct and not D, please.