Chemistry Aldehydes & Ketones BUMHS 2022
PMDC Verified Question 39 of 94
What is the correct IUPAC name of the compound \( C_6H_5-CHO \)?
A
Benzenecarbaldehyde
B
Cyclohexanal
C
Cyclohexyl aldehyde
D
Cyclohexanecarbaldehyde
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option A: Benzenecarbaldehyde
Concept:

When a formyl group (\( -CHO \)) is directly attached to a ring structure, IUPAC nomenclature rules append the suffix "-carbaldehyde" to the full name of the cyclic parent.

Solution:

  • The structure \( C_6H_5-CHO \) represents a formyl group attached directly to a benzene ring.


  • The parent ring is benzene.


  • Adding the proper suffix for the external aldehyde group yields Benzenecarbaldehyde (commonly known as Benzaldehyde, which is also accepted by IUPAC, but Benzenecarbaldehyde is the systematic name).


Why other options are incorrect:

Options B, C, and D refer to a saturated cyclohexane ring, lacking the alternating double bonds (aromaticity) present in the \( C_6H_5 \) phenyl ring.

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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