Solveeit Logo
Login

Question

Question: A compound 'X' evolves CO₂ when treated with NaHCO₃ but gives negative test with tollen's reagent an...

A compound 'X' evolves CO₂ when treated with NaHCO₃ but gives negative test with tollen's reagent and fehling's solution. On treatment with CHCI₃, KOH, a foul smelling organic compound is formed. If 'X' do not give positive iodoform test, which of the following satisfy the conditions to be 'X'.

A

2-amino-4-acetylbenzaldehyde

B

4-aminobenzoic acid

C

Alanine (2-aminopropanoic acid)

D

4-amino-3-oxopentanoic acid

Answer

4-aminobenzoic acid and Alanine (2-aminopropanoic acid)

Explanation

Solution

The compound 'X' must satisfy the following conditions:

  1. Evolves CO₂ when treated with NaHCO₃: This indicates the presence of a carboxylic acid group (-COOH).
  2. Gives negative test with Tollen's reagent and Fehling's solution: This indicates the absence of an aldehyde group (-CHO) and alpha-hydroxy ketone group.
  3. On treatment with CHCl₃, KOH, a foul smelling organic compound is formed: This indicates the presence of a primary amine group (-NH₂). This is the carbylamine reaction.
  4. Do not give positive iodoform test: This indicates the absence of a methyl ketone group (CH3CO-\text{CH}_3\text{CO-}) and a methyl carbinol group (CH3CH(OH)-\text{CH}_3\text{CH(OH)-}).

Let's examine each option:

  • Option A: 2-amino-4-acetylbenzaldehyde. Contains -CHO (aldehyde), -COCH₃ (methyl ketone), and -NH₂ (primary amine). It does not contain -COOH.

    • Reacts with Tollen's/Fehling's (due to aldehyde).
    • Gives positive iodoform test (due to methyl ketone).
    • Gives positive carbylamine test (due to primary amine).
    • Does not evolve CO₂ with NaHCO₃.

    This option does not satisfy the conditions.

  • Option B: 4-aminobenzoic acid. Contains -COOH and -NH₂ (primary amine). It is an aromatic compound.

    • Evolves CO₂ with NaHCO₃ (due to -COOH).
    • Gives negative Tollen's/Fehling's test (no aldehyde or alpha-hydroxy ketone).
    • Gives positive carbylamine test (due to primary amine).
    • Gives negative iodoform test (no methyl ketone or methyl carbinol).

    This option satisfies all the conditions.

  • Option C: Alanine (2-aminopropanoic acid). Contains -COOH and -NH₂ (primary amine). It is an aliphatic compound. The structure is CH3CH(NH2)COOH\text{CH}_3\text{CH(NH}_2)\text{COOH}.

    • Evolves CO₂ with NaHCO₃ (due to -COOH).
    • Gives negative Tollen's/Fehling's test (no aldehyde or alpha-hydroxy ketone).
    • Gives positive carbylamine test (due to primary amine).
    • Gives negative iodoform test (no methyl ketone or methyl carbinol).

    This option satisfies all the conditions.

  • Option D: 4-amino-3-oxopentanoic acid. Contains -COOH, -NH₂ (primary amine), and -COCH₂- (ketone, specifically a methyl ketone CH3CO-\text{CH}_3\text{CO-}). The structure is CH3COCH2CH(NH2)COOH\text{CH}_3\text{COCH}_2\text{CH(NH}_2)\text{COOH}.

    • Evolves CO₂ with NaHCO₃ (due to -COOH).
    • Gives negative Tollen's/Fehling's test (ketones generally don't give these tests unless they are alpha-hydroxy ketones, which this is not).
    • Gives positive carbylamine test (due to primary amine).
    • Gives positive iodoform test (due to methyl ketone CH3CO-\text{CH}_3\text{CO-}).

    This option does not satisfy all the conditions.

Both Option B and Option C satisfy all the given conditions. Since the image shows ticks on both B and C, it is likely a multiple-choice question with multiple correct answers.