Which of the following is not a functional group commonly found in organic molecules?

• A. Amino group
• B. Carboxyl group
• C. Phosphate group
• D. Hydroxyl group

Answer: (C)

Verified step by step guidance

1. Begin by identifying the functional groups listed in the problem: Amino group, Carboxyl group, Phosphate group, and Hydroxyl group.
2. Understand that functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules.
3. Recognize that the amino group (\(\text{NH}_2\)) is commonly found in organic molecules, particularly in amino acids.
4. Identify the carboxyl group (\(\text{COOH}\)) as a common functional group in organic acids, such as acetic acid.
5. Note that the hydroxyl group (\(\text{OH}\)) is a typical functional group in alcohols, like ethanol. The phosphate group (\(\text{PO}_4^{3-}\)) is less common in organic molecules compared to the others listed.