Which term describes a group that is written as -COOH and participates in acidic reactions?

Which term describes a group that is written as -COOH and participates in acidic reactions?

• A. Hydroxyl Group
• B. Ester
• C. Carboxyl Group
• D. Amino Acid

Answer: (C)

The -COOH group is a carboxyl group. It contains a carbonyl carbon (C=O) bonded to a hydroxyl group (–OH) on the same carbon. This arrangement lets the hydrogen on the –OH be donated as H+, so the group can act as an acid and form a carboxylate ion (–COO−) in solution. That proton-donating behavior is what makes it participate in acidic reactions. The hydroxyl group (–OH) alone is not described by the -COOH notation, esters have a –COO– linkage with an alkyl or aryl group (not the acidic –OH hydrogen), and amino acids are molecules that contain a carboxyl group along with other groups, but the term described by -COOH specifically refers to the carboxyl group itself.

The -COOH group is a carboxyl group. It contains a carbonyl carbon (C=O) bonded to a hydroxyl group (–OH) on the same carbon. This arrangement lets the hydrogen on the –OH be donated as H+, so the group can act as an acid and form a carboxylate ion (–COO−) in solution. That proton-donating behavior is what makes it participate in acidic reactions. The hydroxyl group (–OH) alone is not described by the -COOH notation, esters have a –COO– linkage with an alkyl or aryl group (not the acidic –OH hydrogen), and amino acids are molecules that contain a carboxyl group along with other groups, but the term described by -COOH specifically refers to the carboxyl group itself.