PYQ NEET- Aldehydes Ketones And Carboxylic Acids L-4

Question: $\mathrm{CH}_3 \mathrm{CHO}$ and $\mathrm{C}_6 \mathrm{H}_5 \mathrm{CH}_2 \mathrm{CHO}$ can bedistinguished chemically by#

A) Benedict’s test

B) iodoform test

C) Tollens’ reagent test

D) Fehling’s solution test.

Answer: iodoform test#

Sol:#

Acetaldehyde, acetone and methyl ketones having $\mathrm{CH}_3 \mathrm{CO}$ - group undergo haloform reaction. Thus, $\mathrm{CH}_3 \mathrm{CHO}$ will give yellow precipitate with $\mathrm{I}_2$ and $\mathrm{NaOH}$ but $\mathrm{C}_6 \mathrm{H}_5 \mathrm{CH}_2 \mathrm{CHO}$ will not.