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 the following step-by-step approach:

### Step-by-Step Solution:

1. **Identify the Compounds**:
- Propanal (C3H6O) has the structure CH3-CH2-CHO, which is an aldehyde.
- Acetone (C3H6O) has the structure CH3-CO-CH3, which is a ketone.

2. **Select a Suitable Reagent**:
- To differentiate between an aldehyde and a ketone, we need a reagent that selectively reacts with aldehydes but not with ketones. One such reagent is Fehling's solution, which contains copper(II) ions.

3. **Perform the Test**:
- Prepare Fehling's solution by mixing equal volumes of Fehling's A (copper(II) sulfate solution) and Fehling's B (sodium potassium tartrate solution).
- Add a small amount of propanal and acetone separately to different test tubes containing Fehling's solution.

4. **Observe the Reaction**:
- Heat the mixtures gently in a water bath.
- If propanal is present, it will reduce the copper(II) ions (Cu²⁺) to copper(I) oxide (Cu2O), resulting in a brick-red precipitate.
- If acetone is present, there will be no reaction, and the solution will remain blue, indicating that no reduction has occurred.

5. **Conclusion**:
- The formation of a brick-red precipitate indicates the presence of propanal (aldehyde).
- The absence of any color change indicates the presence of acetone (ketone).

### Summary:
By using Fehling's solution, we can distinguish between propanal and acetone based on their reactivity with the reagent. Propanal will yield a positive result (brick-red precipitate), while acetone will not react.

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