When phenol is treated with and concentrated , it yields a deep green/blue color that turns red on dilution and blue again upon adding NaOH. What is the name of this specific phenolic test?

Question

When phenol is treated with $NaNO_2$ and concentrated $H_2SO_4$, it yields a deep green/blue color that turns red on dilution and blue again upon adding NaOH. What is the name of this specific phenolic test?

Prashant Kotian · Accepted Answer

Correct answer: B. Liebermann's nitroso reaction involves the nitrosation of phenol to form p-nitrosophenol, which subsequently condenses with excess phenol to form highly colored indophenol dyes (red in acid, blue/green in base).

💡 Solution & Explanation

Practice 22,000+ questions like this