Question: which one of the following molecules can form hydrogen bonds?
Answer: In other words, hydrogen bonding occurs only in compounds having the highly polar F-H, O-H or N-H bond in their molecules. Examples of such molecules are HF, H2O, NH3(in liqiud state), C2H5OH (ethanol) and other alcohols, and carboxylic acids like CH3COOH (acetic acid).