In the Liebermann's nitroso reaction, sequential changes in the colour of phenol occurs as

Options

A. Brown or red `to` green`to` red`to` deep blue
B. Red `to` deep blue `to` green
C. Red `to` green `to` white
D. White `to` red `to` green

Answer

A

Explanation

In Liebermann nitroso reaction, the uncharged "indophenol" is red, delocalization is less important and the compound is less deeply coloured. But in alkali, the compound becomes deep blue again.
This can be used as a test for phenols.