Question

The acid formed when propyl magnesium bromide is treated with CO_2 followed by acid hydrolysis is:

• A. C_3H_7COOH
• B. C_2H_5COOH
• C. CH_3COOH
• D. C_3H_7OH

Hint:

Grignard reagents react with CO_2 to form carboxylates, which can be hydrolyzed to yield carboxylic acids.

Answer 1

The Correct Option is B

Step 1: Understanding the Reaction 

Propyl magnesium bromide is a Grignard reagent that reacts with carbon dioxide (CO₂) to form a carboxylate anion. This anion is then hydrolyzed to form a carboxylic acid. The reaction can be summarized as follows:

RMgBr + CO₂ → RCO⁻ + MgBr⁺

Upon hydrolysis, the carboxylate anion is converted into a carboxylic acid:

RCO⁻ + H₂O → RCOOH

Step 2: Conclusion

Thus, the acid formed is propionic acid (C₃H₇COOH), corresponding to option (A).

Propionic acid is the correct product of this Grignard reaction with CO₂.