3:C

5)A

1. Approximately 1 mL of 2,4-dinitrophenylhydrazine was placed into 4 separate test tubes.

2. Five drops of ethanol, benzaldehyde, propanone, and unknown Y were added to the 4 test tubes accordin gly.

3. The test tubes were shaken.

4. The formation of a precipitate was observed.

(B) Fehling’s test

1. Approximately 1 mL of ethanol, benzaldehyde, propanone, and unknown Y were placed in 4 separate test tubes.

2. Two mL of Fehling’s solution was added to each test tube.

3. The test tubes were gently shaken.

4. The mixtures were heated in a hot water bath for 15–20 minutes.

5. Observations were recorded.

(C) Tollens’ test

1. Tollens’ reagent was prepared by adding one drop of 10% NaOH to 2 mL of 0.3 M AgNO₃ in a boiling tube.

2. Five percent ammonia was added dropwise until the precipitate dissolved.

3. Approximately 1 mL of ethanol, benzaldehyde, propanone, and unknown Y were placed in separate test tubes.

4. One mL of Tollens’ reagent was added to each test tube, and the mixtures were gently shaken.

5. The mixtures were allowed to stand for 3 minutes. If no change occurred, the mixtures were warmed in a water bath at 60–70°C for 5 minutes.

6. Observations were recorded.

(D) Iodoform test

1. Ten drops of iodine in potassium iodide solution were placed into 3 mL of distilled water in a boiling tube.

2. Five drops of ethanol were added to the boiling tube and shaken gently.

3. Ten percent NaOH was added drop by drop until the color of the iodine faded.

3. The mixture was allowed to stand for 2–3 minutes. If no precipitate formed, the boiling tube was warmed in a water bath at 60–70°C.

4. If the color of iodine disappeared, more iodine in potassium iodide solution was added until the color was retained, and Step 4 was repeated.

5. Observations were recorded.

6. The above steps were repeated with benzaldehyde, propanone, and unknown Y.

Benzaldehyde, propanone and Y - remain unchanged

Benzaldehyde - a mettalic silver mirror deposits on the wall of test tube

Propanone - no metallic silver mirror deposits on the wall of the test tube

Unknown Y - no silver precipitate formed

Propanone,Benzaldehyde and Unknown Y - no yellow precipitate formed