Aldehyde ketones & carboxylic Acid MCQs for NEET — Chemistry Questions with Answers

(c) Semicarbazide is NH₂NHCONH₂.

(c) These are characteristics of C₆H₅CHO.

(a) ${\mathrm{CH}}_3{\mathrm{CHOHCH}}_2\mathrm{CHO}$ is aldol.

The given reaction sequence involves the formation of a tertiary alcohol from the ketone upon reaction with EtMgBr and subsequent dehydration to give a trisubstituted alkene. Ozonolysis of this alkene produces diethyl ketone and acetaldehyde, indicating that the original ketone was diethyl ketone.

Propionaldehyde, upon treatment with dilute NaOH, undergoes aldol condensation, forming a β-hydroxy aldehyde. The product formed is 4-hydroxy-2-methylhexanal, with the given structure.

(b) ${\mathrm{CCl}}_3\mathrm{CHO}\stackrel{{\mathrm{H}}_2\mathrm{O}}{\to }{\mathrm{CCl}}_3\mathrm{CH}(\mathrm{OH}{)}_2$

                             Chloral hydrate

(b) Acid derivatives do not show nucleophilic addition. Also, CH₃COOCOCH₃ is less reactive than CH₃CHO.

The slowest step in the Cannizzaro reaction is the hydride transfer from one aldehyde molecule to another. This step involves the transfer of a hydride ion from the α-carbon of one benzaldehyde molecule to the carbonyl carbon of another, forming a benzyl alcohol and a benzonate ion.

(a) Wolff-Kishner's reaction involves reduction of carbonyl compound into alkane using alkaline hydrazine as reducing agent.