A carbon compound a forms B with sodium metal and again A form C with `PCI_(5)` , but b and C form diethyl ether. Therefore A, and B and C are:

Options

A. `C_(2) H_(5) OH, C_(2) H_(5) Ona, C_(2) H_(5) Cl`
B. `C_(2) H_(5) Cl, C_(2) H_(5) Ona, C_(2) H_(5) OH`
C. `C_(2) H_(5) OH, C_(2) H_(6), C_(2) H_(5) Cl`
D. `C_(2) H_(5) OH, C_(2) H_(5) Cl, C_(2) H_(5) Ona`

Answer

To solve the problem, we need to identify the carbon compounds A, B, and C based on the reactions described. Let's break it down step by step.

### Step 1: Identify Compound A
Compound A is a carbon compound that reacts with sodium metal to form compound B. Given that the final product is diethyl ether, we can deduce that A is likely an alcohol.

**Hint:** Think about common alcohols that could lead to ether formation.

### Step 2: Determine the Structure of A
Since diethyl ether (C2H5)2O is formed from B and C, we can assume that A must have a structure that can produce two ethyl groups. The simplest alcohol that fits this description is ethanol (C2H5OH).

**Hint:** Look for an alcohol that has two carbon atoms.

### Step 3: Reaction of A with Sodium
When ethanol (A) reacts with sodium metal, it forms sodium ethoxide (B) and hydrogen gas. The reaction can be represented as:
\[ \text{C}_2\text{H}_5\text{OH} + \text{Na} \rightarrow \text{C}_2\text{H}_5\text{O}Na + \frac{1}{2}\text{H}_2 \]

Thus, compound B is sodium ethoxide (C2H5O^-Na^+).

**Hint:** Consider the byproducts of the reaction with sodium.

### Step 4: Reaction of A with PCl5
Next, we need to identify compound C, which is formed when A (ethanol) reacts with phosphorus pentachloride (PCl5). The reaction of ethanol with PCl5 produces ethyl chloride (C2H5Cl):
\[ \text{C}_2\text{H}_5\text{OH} + \text{PCl}_5 \rightarrow \text{C}_2\text{H}_5\text{Cl} + \text{POCl}_3 + \text{HCl} \]

Thus, compound C is ethyl chloride (C2H5Cl).

**Hint:** Think about the products formed when alcohols react with PCl5.

### Step 5: Formation of Diethyl Ether
Now, we can see how B (sodium ethoxide) and C (ethyl chloride) combine to form diethyl ether through Williamson synthesis:
\[ \text{C}_2\text{H}_5\text{O}Na + \text{C}_2\text{H}_5\text{Cl} \rightarrow \text{(C}_2\text{H}_5)_2\text{O} + \text{NaCl} \]

This confirms that diethyl ether is formed from the reaction of sodium ethoxide and ethyl chloride.

**Hint:** Recall the mechanism of Williamson synthesis for ether formation.

### Conclusion
Based on the above steps, we can summarize the compounds as follows:
- **A:** Ethanol (C2H5OH)
- **B:** Sodium ethoxide (C2H5O^-Na^+)
- **C:** Ethyl chloride (C2H5Cl)

### Final Answer
- A: Ethanol (C2H5OH)
- B: Sodium ethoxide (C2H5O^-Na^+)
- C: Ethyl chloride (C2H5Cl)