Question

With which of the following does acetic acid not form acyl chloride?

• A. \( \text{PCl}_5 \)
• B. \( \text{PCl}_3 \)
• C. \( \text{SOCl}_2 \)
• D. \( \text{Cl}_2 \)

Hint:

To form acyl chlorides from carboxylic acids, reagents like \( \text{PCl}_3 \), \( \text{PCl}_5 \), and \( \text{SOCl}_2 \) are commonly used.

Answer 1

The Correct Option is D

Step 1: Understanding acyl chloride formation.
Acyl chlorides are typically formed by reacting carboxylic acids with chlorinating agents like \( \text{PCl}_3 \), \( \text{PCl}_5 \), and \( \text{SOCl}_2 \). These reagents react with acetic acid to form acyl chloride. Step 2: Analysis of options.
(A) \( \text{PCl}_5 \): Phosphorus pentachloride reacts with acetic acid to form acyl chloride.
(B) \( \text{PCl}_3 \): Phosphorus trichloride also reacts with acetic acid to form acyl chloride.
(C) \( \text{SOCl}_2 \): Thionyl chloride reacts with acetic acid to form acyl chloride.
(D) \( \text{Cl}_2 \): Chlorine gas does not react with acetic acid to form acyl chloride.
Step 3: Conclusion.
The correct answer is (D) because chlorine gas does not react with acetic acid to form acyl chloride.