What makes a fatty acid an acid? a. It does not dissolve in water. b. It is capable of bonding with other molecules to form a fat. c. It has a carboxyl group that can donate an H+ to a solution. d. It contains only two oxygen atoms.

Verified step by step guidance

1. Identify the functional group in a fatty acid that defines its acidic properties.
2. Understand the role of the carboxyl group (-COOH) in fatty acids.
3. Recognize that the carboxyl group can donate a hydrogen ion (H+) to a solution, which is a characteristic behavior of acids.
4. Evaluate the options given in the question to determine which one correctly describes why a fatty acid is considered an acid.
5. Select the option that mentions the carboxyl group's ability to donate an H+ ion.

Key Concepts

Fatty Acid Structure

Fatty acids are long hydrocarbon chains with a carboxyl group (-COOH) at one end. This carboxyl group is what classifies them as acids, as it can release a hydrogen ion (H+) into a solution, contributing to acidity. The hydrocarbon tail can vary in length and saturation, influencing the fatty acid's properties.

Carboxyl Group

The carboxyl group is a functional group consisting of a carbon atom double-bonded to an oxygen atom and single-bonded to a hydroxyl group (-OH). This structure is responsible for the acidic nature of fatty acids, as it can donate a proton (H+) to a solution, thus lowering the pH and making the solution acidic.

Acid-Base Chemistry

Acid-base chemistry involves the transfer of protons (H+) between molecules. In this context, a substance that can donate protons is classified as an acid. The ability of fatty acids to donate H+ ions due to their carboxyl group is a fundamental aspect of their behavior in biological systems, influencing processes like metabolism and energy storage.