Which of the following sets of compounds are formed as the major organic products when an acetal is hydrolyzed in aqueous $H_{2}O$ and $\mathrm{HCl}$?

• A. A primary alcohol and an alkene
• B. An aldehyde or ketone and two equivalents of alcohol
• C. A diol and a halide
• D. An ether and a carboxylic acid

Answer: (B)

Verified step by step guidance

1. Understand that an acetal is a functional group formed by the reaction of an aldehyde or ketone with two equivalents of an alcohol under acidic conditions.
2. Recall that hydrolysis of an acetal in aqueous acidic conditions (such as H2O and HCl) reverses the formation, breaking the acetal back into its original components.
3. Write the general hydrolysis reaction of an acetal: an acetal reacts with water in the presence of acid to yield the original aldehyde or ketone and two equivalents of the alcohol used to form the acetal.
4. Recognize that the acid (HCl) acts as a catalyst, protonating the acetal oxygen to make it a better leaving group, facilitating the cleavage of the C–O bonds.
5. Conclude that the major organic products of acetal hydrolysis under these conditions are an aldehyde or ketone and two equivalents of alcohol, matching the correct answer.