`C_2H_5OHoverset(PCl_5)rarrX.` In this reaction 'X' is

Options

A. Ethanol
B. Ethylene chloride
C. ethylidene chloride
D. ethyl chloride

Explanation

To solve the question regarding the reaction of ethanol (C₂H₅OH) with phosphorus pentachloride (PCl₅), let's break it down step by step.

### Step 1: Identify the Reactants
The reactants in this reaction are ethanol (C₂H₅OH) and phosphorus pentachloride (PCl₅). Ethanol is an alcohol that contains a hydroxyl (-OH) group.

**Hint:** Remember that the -OH group in alcohols can act as a nucleophile due to the lone pairs on the oxygen atom.

### Step 2: Nucleophilic Attack
In the presence of PCl₅, the oxygen atom in the hydroxyl group of ethanol attacks the phosphorus atom in PCl₅. This is because phosphorus is electrophilic and can accept the lone pair from the oxygen.

**Hint:** Look for the interaction between the nucleophile (oxygen) and the electrophile (phosphorus).

### Step 3: Formation of an Intermediate
When the oxygen attacks phosphorus, one of the chlorine atoms (Cl) from PCl₅ leaves as a chloride ion (Cl⁻). This results in the formation of an intermediate compound, which can be represented as C₂H₅OPCl₄.

**Hint:** Keep track of the leaving group; in this case, Cl⁻ is a good leaving group.

### Step 4: Further Reaction of the Intermediate
The intermediate C₂H₅OPCl₄ can undergo further reactions. The remaining chlorine atoms in the intermediate can now act as nucleophiles. One of these chlorine atoms can attack the carbon atom of the ethyl group (C₂H₅), leading to the substitution of the hydroxyl group.

**Hint:** Consider how the intermediate can rearrange or react further to yield a stable product.

### Step 5: Final Product Formation
As a result of the nucleophilic attack by the chlorine atom, we get ethyl chloride (C₂H₅Cl) as the final product. Additionally, phosphorus oxychloride (POCl₃) and hydrochloric acid (HCl) are also formed as by-products.

**Hint:** Remember to account for all products formed in the reaction, including by-products.

### Conclusion
Thus, the final product 'X' in the reaction of ethanol with PCl₅ is ethyl chloride (C₂H₅Cl).

### Final Answer
**X = C₂H₅Cl (ethyl chloride)**

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