Question

Which of the following aqueous solutions can be added to the reaction to separate the amide and carboxylic acid products through extraction (Note: R_1 and R_2 = long hydrocarbon chains) A. 5% NaCl B. 5% CH₃CO₂H C. 5% NaHCO₃ D. 5% CH₃O H

Answer 1

To separate amide and carboxylic acid products through extraction, a 5% NaHCO₃ solution can be added since it will react with carboxylic acids to form a water-soluble salt, thereby allowing the amide to remain in the organic layer.

Step-by-step explanation:

The question asks which aqueous solution can be used to separate amide and carboxylic acid products through extraction. During the hydrolysis of an amide, the basic hydrolysis yields a salt of the carboxylic acid and an amine or ammonia, whereas acid hydrolysis yields the carboxylic acid and the salt of ammonia or an amine.

For separating the amide from the carboxylic acid, one would typically want to react the carboxylic acid to form a water-soluble salt, which would then dissolve in the aqueous layer during an extraction procedure. The best choice for this reaction would be Option C: 5% NaHCO₃, as it reacts with carboxylic acids to produce water-soluble sodium carboxylate salts and carbon dioxide gas. This will leave the amide in the organic layer allowing for its separation from the carboxylic acid.

• Amide and carboxylic acid would be present in different phases post-extraction.
• NaHCO₃ is basic and will only react with the carboxylic acid, not the amide.
• Neutral amines from the amide hydrolysis will not be protonated by NaHCO₃, and therefore will not move into the aqueous phase.