Question

Phenol $\stackrel{NaN{O}_2|H_{2}S{O}_4}{\to }B\stackrel{H_{2}O}{\to }C\stackrel{NaOH}{\to }D$ name of the reaction is :

• A. Liebermann's reaction
• B. Phthalein fusion test
• C. Reimer Tiemann reaction
• D. Schotten-Baumann reaction

Answer 1

The correct option is A Liebermann's reaction

The name of the reaction is Liebermann's reaction. It is a test for phenol.
$C_6{H}_5-OH\stackrel{NaN{O}_2|H_{2}S{O}_4}{\to }\underset{\text{deep green or blue colour}}{B}\stackrel{H_{2}O}{\to }\underset{red}{C}\stackrel{NaOH}{\to }\underset{Blue}{D}$
When phenol is reacted with sodium nitrite and concentrated sulphuric acid, it gives a deep green or blue colour which changes to red on dilution with water. When made alkaline with NaOH, the red colour changes back to original green or blue colour.