Chemistry Aldehydes & Ketones NUMS 2024
PMDC Verified Question 12 of 94
Compound A + \( I_2 \) + \( Na_2CO_3 \) \(\longrightarrow\) compound B + \( RCOONa \) + \( NaI \) + \( H_2O \). Identify compound B (Wrong)
A
Acetone
B
Acetamide
C
Acetic acid
D
Acetic anhydride
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option A: Acetone
Concept:

The given chemical equation represents the Haloform (Iodoform) Reaction, typically carried out on methyl ketones using Iodine and a mild base.

Solution:

  • The true identity of Compound B (the precipitated haloform product) in this reaction should be Iodoform (\( CHI_3 \)).


  • However, Iodoform is missing from the options. The textbook specifically flags this question as "Wrong" in the original paper.


  • The answer key selects Acetone. In reality, Acetone is the reactant (Compound A) that undergoes the reaction:
    $$ CH_3COCH_3 + 3I_2 + 4NaOH \longrightarrow CHI_3 + CH_3COONa + 3NaI + 3H_2O $$


  • Since Acetone is the only chemical structurally capable of participating in this specific reaction scheme among the choices, it is marked as the "intended" answer by the examiner, despite being labelled as the wrong variable in the prompt.


Why other options are incorrect:

Acetamide, Acetic acid, and Acetic anhydride do not undergo the haloform reaction. They lack the reactive terminal methyl group adjacent to an easily cleaved carbonyl center.

Quality & Fidelity Assurance: Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.

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