Which of the following functional groups is present in a compound with the molecular formula $C_{10}{H}_{12}{O}_2$ that is commonly known as vanillin?

• A. Amine
• B. Carboxylic acid
• C. Ketone
• D. Aldehyde

Answer: (D)

Verified step by step guidance

1. Step 1: Identify the molecular formula given, which is \(C_{10}H_{12}O_2\), and recognize that the compound is vanillin, a well-known organic molecule.
2. Step 2: Recall the common functional groups present in vanillin by considering its structure: vanillin contains an aromatic ring, a hydroxyl group (-OH), a methoxy group (-OCH_3), and a formyl group (-CHO).
3. Step 3: Understand the nature of the formyl group (-CHO), which is characteristic of an aldehyde functional group. This group consists of a carbonyl carbon bonded to a hydrogen atom.
4. Step 4: Differentiate aldehydes from other carbonyl-containing groups such as ketones (carbonyl bonded to two carbons) and carboxylic acids (carbonyl bonded to a hydroxyl group). Vanillin does not have these groups.
5. Step 5: Conclude that the functional group present in vanillin corresponding to the molecular formula and common name is the aldehyde group.