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.

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.