Give a chemical test to distinguish between propanal and propanoic acid.

Explanation

To distinguish between propanal (an aldehyde) and propanoic acid (a carboxylic acid), we can use the Tollens' reagent test. Here’s a step-by-step solution:

### Step 1: Understand the Structures
- **Propanal**: The chemical structure is CH₃CH₂CHO.
- **Propanoic Acid**: The chemical structure is CH₃CH₂COOH.

### Step 2: Identify the Reagent
- Use **Tollens' reagent**, which is a solution of silver nitrate (AgNO₃) in ammonia (NH₃). This reagent is specifically used to test for aldehydes.
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