An organic compound 'X' having molecular formula `C_(5)H_(10)O` yield phenylhydrazone and gives negative response to the iodoform test and Tollens test . It produces n-pentane on reduction. 'X' could be

Options

A. Pentanal
B. 2-pentanone
C. 3-pentanone
D. n-amyl alcohol

Explanation

To solve the problem, let's break down the information given about the organic compound 'X' with the molecular formula \( C_5H_{10}O \) step by step.

### Step 1: Analyze the Molecular Formula
The molecular formula \( C_5H_{10}O \) indicates that the compound contains 5 carbon atoms, 10 hydrogen atoms, and 1 oxygen atom. This suggests that the compound could be an aldehyde or a ketone, as both types of compounds can have this formula.

**Hint:** Look for functional groups that can be derived from the molecular formula.

### Step 2: Identify the Functional Group
The problem states that compound 'X' yields phenylhydrazone when treated with phenylhydrazine. This indicates that 'X' must contain a carbonyl group (C=O), as only carbonyl compounds can react with phenylhydrazine to form hydrazones.

**Hint:** Remember that phenylhydrazone formation is characteristic of carbonyl compounds.

### Step 3: Consider the Test Results
The compound gives a negative response to the Iodoform test and the Tollens test.
- A negative Tollens test indicates that 'X' is not an aldehyde since aldehydes typically give a positive Tollens test.
- A negative Iodoform test suggests that 'X' does not have a methyl ketone structure (i.e., a carbonyl group bonded to a methyl group).

**Hint:** Use the test results to eliminate possible structures.

### Step 4: Determine the Type of Compound
Since 'X' is confirmed to be a ketone (due to the negative Tollens test) and it does not have a methyl group adjacent to the carbonyl (due to the negative Iodoform test), we can conclude that 'X' must be a ketone that does not have a terminal methyl group.

**Hint:** Focus on the structural possibilities of ketones with 5 carbon atoms.

### Step 5: Identify Possible Ketones
For the formula \( C_5H_{10}O \), the possible ketones are:
1. 2-Pentanone (CH3-CO-CH2-CH2-CH3)
2. 3-Pentanone (CH3-CH2-CO-CH2-CH3)

Both of these structures are valid ketones. However, we need to determine which one fits the criteria of not giving a positive Iodoform test.

**Hint:** Draw the structures of the possible ketones and check for the presence of a methyl group adjacent to the carbonyl.

### Step 6: Check Iodoform Test
- **2-Pentanone**: This ketone has a methyl group adjacent to the carbonyl (C=O), so it would give a positive Iodoform test.
- **3-Pentanone**: This ketone does not have a methyl group adjacent to the carbonyl, so it would give a negative Iodoform test.

Since 'X' gives a negative Iodoform test, it must be **3-Pentanone**.

**Hint:** Confirm the structure of 3-pentanone and ensure it matches all the criteria given in the problem.

### Step 7: Conclusion
Based on the analysis, the organic compound 'X' with the molecular formula \( C_5H_{10}O \), which yields phenylhydrazone, gives negative responses to both the Iodoform and Tollens tests, and produces n-pentane upon reduction, is **3-Pentanone**.

**Final Answer:** \( \text{X} = \text{3-Pentanone} \)