Question

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R) 
Assertion (A): \(\alpha\)-halocarboxylic acid on reaction with dil \(NH _3\) gives good yield of \(\alpha\)-aminocarboxylic acid whereas the yield of amines is very low when prepared from alkyl halides 
Reason (R): Amino acids exist in zwitter ion form in aqueous medium 
In the light of the above statements, choose the correct answer from the options given below :

• A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
• B. (A) is not correct but (R) is correct
• C. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
• D. $( A )$ is correct but $( R )$ is not correct

Hint:

Carefully analyze the relationship between the assertion and the reason. Even if both are true independently, the reason might not be the correct explanation for the assertion.

Answer 1

The Correct Option is C

To solve the given question, we need to analyze both the Assertion (A) and Reason (R) and determine the relationship between them.

1. Assertion (A):

   \(\alpha\)-halocarboxylic acid on reaction with dilute \(\text{NH}_3\) gives a good yield of \(\alpha\)-aminocarboxylic acid whereas the yield of amines is very low when prepared from alkyl halides.

   This statement is correct. The reaction of \(\alpha\)-halocarboxylic acid with ammonia results in \(\alpha\)-aminocarboxylic acid due to the presence of the carboxylic group, which stabilizes the transition state and facilitates nucleophilic substitution. Conversely, alkyl halides do not have such groups, leading to lower yields of amines due to the competing elimination reactions and steric hindrance.

2. Reason (R):

   Amino acids exist in zwitter ion form in aqueous medium.

   This statement is also correct. Amino acids contain both acidic (carboxylic) and basic (amino) groups, which allow them to exist as zwitterions (species with both positive and negative charges) in an aqueous medium. This property influences their solubility and reactivity.

3. Evaluation:

   While both statements are correct, the reason provided (R) does not directly explain why \(\alpha\)-halocarboxylic acids result in better yields of \(\alpha\)-aminocarboxylic acids compared to alkyl halides. The assertion is more related to the stability and reactivity of intermediates and not the zwitterionic nature of amino acids.

Based on the above analysis, we conclude that the correct answer is: Both (A) and (R) are correct but (R) is not the correct explanation of (A).