JEE Main 2025 — 8 April, Evening Shift — Question 15

(A) Carboxylic acid gives effervescence with sodium bicarbonate

$\mathrm{R}-\mathrm{COOH}+\mathrm{NaHCO}_{3} \rightarrow \mathrm{RCOONa}+\mathrm{CO}_{2} \uparrow+\mathrm{H}_{2} \mathrm{O}$

(B) Phenolic-OH gives characteristic colour with neutral $\mathrm{FeCl}_{3}$

(C) Alcoholic-OH gives red colour with ceric ammonium nitrate

$\left(\mathrm{NH}_{4}\right)_{2}\left[\mathrm{Ce}\left(\mathrm{NO}_{3}\right)_{6}\right]+2 \mathrm{ROH} \rightarrow \underset{\text { (Red) }}{\left[\mathrm{Ce}(\mathrm{ROH})_{2}\left(\mathrm{NO}_{3}\right)_{4}\right]+2 \mathrm{NH}_{4} \mathrm{NO}_{3}}$

(D) Purple colour of alkaline $\mathrm{KMnO}_{4}$ is discharged by multiple bond of alkenes and alkynes