`CH_(3)CHO and C_(6)H_(5)CH_(2)CHO` can be distinguished chemically by

Options

A. Benedict test
B. iodoform test
C. Tollen's reagent test
D. Fehling solution

Explanation

To distinguish between CH₃CHO (acetaldehyde) and C₆H₅CH₂CHO (benzaldehyde), we can use the Iodoform test. Here’s the step-by-step solution:

### Step 1: Identify the Compounds
- CH₃CHO is acetaldehyde, which contains the aldehyde functional group (CHO).
- C₆H₅CH₂CHO is benzaldehyde, which also contains the aldehyde functional group (CHO).

### Step 2: Understand the Iodoform Test
- The Iodoform test is a chemical reaction used to identify compounds that contain the methyl ketone group (CH₃CO) or ethanol (CH₃CH₂OH) derivatives.
- In the presence of iodine (I₂) and sodium hydroxide (NaOH), compounds containing the CH₃CO group will react to form a yellow precipitate of iodoform (CHI₃).

### Step 3: Analyze the Structure of Each Compound
- Acetaldehyde (CH₃CHO) can be represented as CH₃C(=O)H, which contains the CH₃CO group.
- Benzaldehyde (C₆H₅CH₂CHO) can be represented as C₆H₅CH₂C(=O)H, which does not contain the CH₃CO group.

### Step 4: Perform the Iodoform Test
- When acetaldehyde (CH₃CHO) is treated with I₂ and NaOH, it will produce a yellow precipitate of iodoform (CHI₃), indicating a positive test.
- When benzaldehyde (C₆H₅CH₂CHO) is treated with I₂ and NaOH, it will not produce any precipitate, indicating a negative test.

### Step 5: Conclusion
- The Iodoform test can distinguish between the two aldehydes:
- **Positive Iodoform Test**: Acetaldehyde (CH₃CHO)
- **Negative Iodoform Test**: Benzaldehyde (C₆H₅CH₂CHO)

### Final Answer
The chemical distinction between CH₃CHO and C₆H₅CH₂CHO can be made using the Iodoform test.

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