Question

Identify 'A' in the following reaction
C\(_2\)H\(_5\)OH + HCl \(\xrightarrow{A}\) C\(_2\)H\(_5\)Cl + H\(_2\)O

• A. anhydrous ZnCl\(_2\)
• B. pyridine
• C. conc. H\(_2\)SO\(_4\)
• D. NaNO\(_2\)

Hint:

Anhydrous ZnCl\(_2\) is commonly used as a catalyst in the conversion of alcohols to alkyl chlorides via nucleophilic substitution.

Answer 1

The Correct Option is A

Step 1: Understanding the reaction.
The reaction involves the substitution of the hydroxyl group in ethanol (C\(_2\)H\(_5\)OH) with a chlorine atom to form ethyl chloride (C\(_2\)H\(_5\)Cl). This is a nucleophilic substitution reaction.

Step 2: Analyzing the options.
(A) anhydrous ZnCl\(_2\): Correct — Anhydrous ZnCl\(_2\) is commonly used as a catalyst for this reaction because it helps in the activation of the hydroxyl group for nucleophilic substitution.
(B) pyridine: Pyridine is often used in reactions involving acid chlorides, not for substitution reactions like this one.
(C) conc. H\(_2\)SO\(_4\): Concentrated sulfuric acid is a dehydrating agent and may be used in some substitution reactions but not specifically for this one.
(D) NaNO\(_2\): Sodium nitrite is used in diazotization reactions, not in this type of substitution reaction.

Step 3: Conclusion.
The correct reagent is (A) anhydrous ZnCl\(_2\).