Which of the following compound can from hydrazone and will give iodoform test but will not give Tollen's test ?

Options

A.
B. `H_(3)C-underset(O)underset(||)(C)-CH_(2)-CH_(3)`
C. `H_(3)C-underset(O)underset(||)(C)-CH_(2)-CHO`
D. `CH_(3)-CH_(2)-OH`

Answer

To solve the question, we need to analyze the requirements for the compound in question. The compound must:

1. Form a hydrazone.
2. Give a positive iodoform test.
3. Not give a positive Tollen's test.

Let's break down the solution step by step:

### Step 1: Understanding Hydrazone Formation
Hydrazones are formed from aldehydes and ketones when they react with hydrazine (NH2NH2). Therefore, any compound that is either an aldehyde or a ketone can form a hydrazone.

**Hint:** Remember that only aldehydes and ketones can form hydrazones.

### Step 2: Conditions for Iodoform Test
The iodoform test is positive for compounds that have the structure RCOCH3 (where R can be any alkyl or aryl group). This means that the compound must have a methyl group (CH3) adjacent to the carbonyl group (C=O).

**Hint:** Look for a methyl group next to the carbonyl group to confirm a positive iodoform test.

### Step 3: Conditions for Tollen's Test
The Tollen's test is positive for all aldehydes and alpha-hydroxy ketones. Therefore, to satisfy the condition of not giving a Tollen's test, the compound must be a ketone that does not have an aldehyde or an alpha-hydroxy ketone structure.

**Hint:** Identify if the compound is a ketone without an aldehyde or alpha-hydroxy group to ensure a negative Tollen's test.

### Step 4: Analyzing the Options
Now, we will analyze the given options one by one:

1. **Option 1: C=O, CH2, CH3**
- This is a ketone but does not have a methyl group adjacent to the carbonyl. It cannot give a positive iodoform test.
- **Conclusion:** Does not satisfy all conditions.

2. **Option 2: CH3, C=O, CH2, CH3**
- This is a ketone with a methyl group adjacent to the carbonyl. It can form a hydrazone and will give a positive iodoform test.
- It does not have an aldehyde or alpha-hydroxy group, so it will not give a Tollen's test.
- **Conclusion:** Satisfies all conditions.

3. **Option 3: CH3, C=O, CH2, CHO**
- This compound has both a ketone and an aldehyde. It can form a hydrazone and will give a positive iodoform test. However, it will also give a positive Tollen's test due to the presence of the aldehyde.
- **Conclusion:** Does not satisfy all conditions.

4. **Option 4: Alcohol**
- An alcohol cannot form a hydrazone, and while it may give a positive iodoform test, it does not satisfy the requirement of forming a hydrazone.
- **Conclusion:** Does not satisfy all conditions.

### Final Answer
Based on the analysis, **Option 2** is the only compound that can form a hydrazone, gives a positive iodoform test, and does not give a Tollen's test.

**Correct Answer:** Option 2