Which of the following compounds will react with Tollens' reagent? With Benedict's reagent?
a. Cyclopentanon
b. Hexanal
c.

Verified step by step guidance

1. Step 1: Understand the reagents. Tollens' reagent is a mild oxidizing agent that reacts with aldehydes to form a silver mirror, but it does not react with ketones. Benedict's reagent is another oxidizing agent that reacts with aldehydes and reducing sugars, but not with ketones.
2. Step 2: Analyze compound (a), Cyclopentanone. Cyclopentanone is a ketone, as indicated by the '-one' suffix. Ketones do not have a hydrogen atom attached to the carbonyl carbon, so they do not react with either Tollens' or Benedict's reagent.
3. Step 3: Analyze compound (b), Hexanal. Hexanal is an aldehyde, as indicated by the '-al' suffix. Aldehydes have a hydrogen atom attached to the carbonyl carbon, making them reactive with both Tollens' and Benedict's reagents. Hexanal will react with both reagents.
4. Step 4: Analyze compound (c), represented by the image. Carefully examine the structure in the image to determine if it contains an aldehyde group (–CHO) or a ketone group (C=O). If it has an aldehyde group, it will react with both reagents. If it has a ketone group, it will not react with either reagent.
5. Step 5: Summarize the reactivity of each compound. Cyclopentanone does not react with either reagent, Hexanal reacts with both reagents, and the reactivity of the compound in the image depends on its functional group (aldehyde or ketone).

Key Concepts

Tollens' Reagent

Tollens' reagent is a solution of silver nitrate in ammonia, used to test for aldehydes. When an aldehyde is present, it reduces the silver ions to metallic silver, resulting in a characteristic silver mirror on the test container. This reagent does not react with ketones, making it a selective test for aldehydes.

Benedict's Reagent

Benedict's reagent is a blue solution containing copper(II) sulfate, which is used to test for reducing sugars and aldehydes. When heated with a reducing sugar or an aldehyde, the copper(II) ions are reduced to copper(I) oxide, forming a colored precipitate ranging from green to brick red, depending on the amount of reducing sugar present.

Aldehydes vs. Ketones

Aldehydes and ketones are both carbonyl compounds, but they differ in structure and reactivity. Aldehydes have the carbonyl group at the end of the carbon chain, making them more reactive towards oxidizing agents like Tollens' and Benedict's reagents. In contrast, ketones have the carbonyl group within the carbon chain and generally do not react with these reagents.