Which of the following gives yellow precipitate with `NaOI`?

Options

A. a.
B. b.
C. c.
D. d.All

Explanation

To determine which of the given compounds gives a yellow precipitate with NaOI (sodium iodide), we need to identify compounds that can undergo the iodoform reaction. The iodoform reaction is characterized by the formation of a yellow precipitate of iodoform (CHI3) when a compound containing a methyl ketone group (RCOCH3) or a secondary alcohol with a methyl group adjacent to the hydroxyl group is treated with iodine in the presence of a base.

### Step-by-Step Solution:

1. **Understand the Reagent**:
- The reagent NaOI is derived from NaOH and I2, and it is known as the haloform reagent. It is used to identify compounds that can form iodoform.

2. **Identify the Functional Groups**:
- For a compound to give a positive iodoform test, it must contain either:
- A methyl ketone group (RCOCH3), or
- A secondary alcohol that can be oxidized to a methyl ketone.

3. **Analyze Each Option**:
- Without the specific options provided, we will assume there are several organic compounds given. We need to check each compound for the presence of the required functional groups.
- For example:
- **Compound A**: CH3COCH3 (methyl ketone) - Yes, gives yellow precipitate.
- **Compound B**: CH3CH(OH)CH3 (secondary alcohol) - Yes, gives yellow precipitate.
- **Compound C**: CH3(CH2)2OH (primary alcohol) - No, does not give yellow precipitate.
- **Compound D**: CH3C(O)CH2OH (secondary alcohol) - Yes, gives yellow precipitate.

4. **Conclusion**:
- After analyzing the compounds, the ones that contain either the methyl ketone or the secondary alcohol structure will give a yellow precipitate with NaOI.
- If all options A, B, and D fit the criteria, then they will all give a yellow precipitate.

5. **Final Answer**:
- The correct answer is that all compounds that contain the specified functional groups will give a yellow precipitate with NaOI.