What is X in the following reaction ?
`C_2H_5Cl +X rarrC_2H_5OH + KCl`

Options

A. `KHCO_3`
B. Alcoholic KOH
C. Aqueous KON
D. `K_2CO_3`

Explanation

To determine what X is in the reaction `C2H5Cl + X → C2H5OH + KCl`, we need to analyze the reaction step by step.

### Step 1: Identify the Reaction Type
The given reaction is between ethyl chloride (C2H5Cl) and an unknown reactant X, producing ethyl alcohol (C2H5OH) and potassium chloride (KCl). This indicates a substitution reaction where the chlorine atom in C2H5Cl is replaced by a hydroxyl group (OH).

**Hint:** Look for a reactant that can provide the hydroxyl group (OH) to replace the chlorine atom.

### Step 2: Recognize the Nucleophile
In this reaction, the hydroxyl group (OH) is acting as a nucleophile. For the substitution to occur, we need a source of hydroxide ions (OH-) that can attack the carbon atom bonded to chlorine.

**Hint:** Consider common bases that can provide hydroxide ions in solution.

### Step 3: Identify Possible Candidates for X
The reactant X must be a source of hydroxide ions. One common source is potassium hydroxide (KOH). When KOH is dissolved in water, it dissociates to give K+ and OH- ions.

**Hint:** Think about the dissociation of strong bases in aqueous solutions.

### Step 4: Write the Complete Reaction
When KOH is used as X, the reaction can be written as:
\[ C2H5Cl + KOH → C2H5OH + KCl \]
In this reaction, the OH- ion attacks the carbon atom, leading to the substitution of the chlorine atom with the hydroxyl group.

**Hint:** Ensure that the products of the reaction match what is given in the question.

### Step 5: Conclusion
Based on the analysis, the reactant X that allows the reaction to occur is potassium hydroxide (KOH).

**Final Answer:** X is KOH.