Which of the following molecules is amphipathic?

A) CH3CH2OH

B) CH3 (CH2) 10CO2H

C) CH3 (CH2) 10CH3

D) CH3CO2H

B) CH3 (CH2) 10CO2H

Explanation:

Hello,

In this case, we define amphipathic as a compound having both a hydrophilic and a hydrophobic part, for that reason, the hydrophilic part will be water-soluble (polar) whereas the hydrophobic does not (nonpolar). In such a way, some functional groups such as hydroxyl and carboxyl tend to be polar by cause of the presence of O-H bonds whereas long-carboned chains tend to be nonpolar by cause of the presence of C-H and C-C bonds.

Therefore, since A) CH3CH2OH (ethanol) and D) CH3CO2H (acetic acid) are short-carboned chains with polar groups they are largely hydrophilic whereas C) CH3 (CH2) 10CH3 (dodecane) is highly nonpolar, we sum up that only B) CH3 (CH2) 10CO2H (dodecanoic acid or lauric acid) is amphoteric as it has a long-charboned part (nonpolar) and a water-soluble part (polar).

Best regards.