Which organic compound is responsible for the characteristic aroma of fruits?

1. Analyze the question

The question asks for the specific class of organic compounds that gives fruits their distinct, pleasant, and characteristic smell (aroma).

2. Explain the concept

In organic chemistry, different functional groups give compounds unique physical and chemical properties.

• Alkanes are generally odorless or have a faint "petrol-like" smell.
• Alkynes are unsaturated hydrocarbons and do not typically have fruity aromas.
• Esters are formed by the reaction between a carboxylic acid and an alcohol (esterification). They are well-known in chemistry for having sweet, pleasant, and fruity odors. Many synthetic flavorings and perfumes are actually esters.
• Amines are derivatives of ammonia and are notorious for having strong, fishy, or unpleasant odors.

3. Show the solution

• Step 1: Identify the functional group responsible for the "fruity" smell.
• Step 2: Recall the properties of esters. Esters have the general formula $RCOOR'$. They are widely used in the food industry to create artificial fruit flavors (e.g., isoamyl acetate smells like bananas, and ethyl butyrate smells like pineapples).
• Step 3: Compare this with the other options. Since alkanes, alkynes, and amines do not possess the characteristic sweet, fruity scent associated with esters, we can confidently eliminate them.

4. Identify the answer

The correct option is C.

5. Exam Tip

Memory Trick: Think of the word "Ester" as sounding like "Easter"—a time when people often enjoy sweet treats and fruits. Also, remember the mnemonic: "Esters are sweet, Amines are fishy." This simple contrast will help you remember their odors during your exam!