Which of the following statements correctly describes the polarity of fatty acid chains?

• A. Fatty acid chains are polar due to the presence of a carboxyl group ($\mathrm{COOH}$).
• B. Fatty acid chains are nonpolar because they consist mainly of hydrocarbon chains ($\mathrm{CH}{2}_{}-\mathrm{CH}{2}_{}-\mathrm{CH}{3}_{}$).
• C. Fatty acid chains are nonpolar due to their ability to form hydrogen bonds ($H-\mathrm{bond}$).
• D. Fatty acid chains are polar because they can dissolve in water ($H{2}_{}O$).

Answer: (B)

Verified step by step guidance

1. Identify the structure of a typical fatty acid, which consists of a long hydrocarbon chain and a terminal carboxyl group.
2. Understand that the hydrocarbon chain is composed of carbon and hydrogen atoms, which form nonpolar covalent bonds due to similar electronegativities.
3. Recognize that the carboxyl group (-COOH) at the end of the fatty acid is polar because of the difference in electronegativity between oxygen and hydrogen, allowing it to form hydrogen bonds.
4. Consider the overall structure of the fatty acid: while the carboxyl group is polar, the long hydrocarbon chain is nonpolar, making the entire molecule predominantly nonpolar.
5. Conclude that fatty acid chains are generally nonpolar because the extensive hydrocarbon chain outweighs the small polar carboxyl group, leading to limited solubility in water.