Answer: The answer is D. This has a Carboxylic Acid group, and is acetic acid, or Ethanoic Acid.
ALWAYS LOOK for the Functional Group in question.
A. Would likely not stay in water, or at least not be acidic, for it is butane gas.
B. Is 1-propanol, and alcohols are not acidic as a rule. Certainly not in water.
C. This is an Ether. It will not give up an H+, it it not an acid.
E. This functional group is an amine, which is more “base” like, since the lone pairs of the Nitrogen atom would tend to attract a H+.
