Propanal and Acetone can be distinguished by testing with

Options

A. Phenyl hydrazine
B. Hydroxylamine
C. Fehling solution
D. Sodium bisulphite

Answer

To distinguish between propanal (an aldehyde) and acetone (a ketone), we can use Fehling's solution. Here’s a step-by-step solution:

### Step 1: Identify the Compounds
- **Propanal**: CH3CH2CHO (an aldehyde)
- **Acetone**: CH3COCH3 (a ketone)

### Step 2: Choose the Reagent
- We will use **Fehling's solution**, which contains copper(II) ions in a basic medium. This reagent is known to react with aldehydes but not with ketones.

### Step 3: Conduct the Test
1. Take a small amount of propanal and mix it with Fehling's solution.
2. Heat the mixture gently.

### Step 4: Observe the Reaction
- **For Propanal**: The deep blue color of the Fehling's solution will change to a brick-red precipitate of copper(I) oxide (Cu2O). This indicates that propanal has been oxidized to a carboxylic acid (propanoic acid).

Reaction:
\[ \text{CH}_3\text{CH}_2\text{CHO} + 2 \text{Cu}^{2+} + 5 \text{OH}^- \rightarrow \text{CH}_3\text{CH}_2\text{COOH} + \text{Cu}_2\text{O} (s) + 3 \text{H}_2\text{O} \]

- **For Acetone**: There will be no change; the solution will remain blue, indicating that acetone does not react with Fehling's solution.

### Step 5: Conclusion
- The presence of a brick-red precipitate indicates the presence of propanal (an aldehyde), while no change indicates the presence of acetone (a ketone). Thus, propanal and acetone can be distinguished using Fehling's solution.