Which of the following best describes an organic peroxide functional group?

• A. A compound containing a carbonyl group ($C=O$)
• B. A compound containing an oxygen-oxygen single bond ($R-O-O-R$) where $R$ is a carbon-containing group
• C. A compound containing a hydroxyl group ($O-H$)
• D. A compound containing a nitro group ($N{O}_2$)

Answer: (B)

Verified step by step guidance

1. Understand that an organic peroxide functional group is characterized by the presence of an oxygen-oxygen single bond, often written as \( R-\!O-\!O-\!R \), where \( R \) represents a carbon-containing group.
2. Recall that a carbonyl group is a carbon double bonded to oxygen, \( C=O \), which is found in aldehydes, ketones, carboxylic acids, and related compounds, but not in peroxides.
3. Recognize that a hydroxyl group, \( -OH \), is characteristic of alcohols and phenols, and does not contain an oxygen-oxygen bond.
4. Note that a nitro group, \( -NO_2 \), contains nitrogen bonded to two oxygens but does not have an oxygen-oxygen single bond, so it is not a peroxide.
5. Conclude that the defining feature of an organic peroxide is the \( O-O \) single bond linking two carbon-containing groups, making the structure \( R-\!O-\!O-\!R \) the correct description.