The product of adding two molecules of an alcohol to an aldehyde in the presence of acid is a(n):

a. acetal.
b. hemiether.
c. ether.
d. hemiacetal.
e. hydroxyl group.

A

Explanation:

Acetals are geminal-diether derivatives of aldehydes or ketones, formed by reaction with two equivalents (or an excess amount) of an alcohol and elimination of water. Ketone derivatives of this kind were once called ketals, but modern usage has dropped that term.

To achieve effective hemiacetal or acetal formation, two additional features must be implemented. First, an acid catalyst must be used because alcohol is a weak nucleophile and second the water produced with the acetal must be removed from the reaction.

a. acetal

Explanation:

In the presence of an acid, the alcohol molecules are aided to form a bond with the aldehydes in both two dimensional geometry and as a result of this bond formation an acetal forms.