Which of the following group(s) is/are identified by the haloform reaction?

Options

A. `CH_3CO` group
B. `CH_3CH(OH)` group
C. `CH_3-O` group
D. Both (1) and (2)

Answer

To determine which group(s) are identified by the haloform reaction, we first need to understand what the haloform reaction is and how it works.

### Step-by-Step Solution:

1. **Understanding the Haloform Reaction**:
- The haloform reaction involves the reaction of a methyl ketone (or a compound that can be converted into a methyl ketone) with halogens (usually iodine) in the presence of a strong base (like sodium hydroxide, NaOH).
- The general reaction can be represented as:
\[ RCOCH_3 + 3I_2 + 4NaOH \rightarrow RCOONa + 3NaI + 3H_2O + CHI_3 \]
- The product CHI₃ is known as iodoform, which is a yellow precipitate that indicates a positive result for the presence of a methyl ketone.

2. **Identifying the Functional Groups**:
- The haloform reaction is specifically used to identify methyl ketones (RCOCH₃) and some secondary alcohols that can be oxidized to methyl ketones.
- For example, acetone (CH₃COCH₃) and ethanol (CH₃CH₂OH) can be tested using this reaction.

3. **Analyzing the Given Options**:
- **Option 1: CH₃C(O)NaO** - This represents a methyl ketone, which can undergo the haloform reaction.
- **Option 2: CH₃CHOH** - This is an alcohol that can be oxidized to a methyl ketone, thus it can also give a positive haloform reaction.
- **Option 3: CH₃C(O)H** - This is an aldehyde, which does not undergo the haloform reaction.
- **Option 4: HCOO-** - This is a carboxylate ion and does not participate in the haloform reaction.

4. **Conclusion**:
- The groups that can be identified by the haloform reaction are primarily methyl ketones and certain secondary alcohols that can be oxidized to methyl ketones.
- Therefore, the correct answer would be **Option 1 (CH₃C(O)NaO)** and **Option 2 (CH₃CHOH)**.

### Final Answer:
The groups identified by the haloform reaction are **methyl ketones (like CH₃C(O)NaO)** and **secondary alcohols (like CH₃CHOH)**.

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