Phenol is heated with pthalic anhydride in the presence of concentrated H₂SO₄.

Phenol is heated with pthalic anhydride in the presence of concentrated H₂SO₄.The product gives pink colour with alkali. The product is

Options

(a) salicylic acid
(b) bakelite
(c) phenolphthalein
(d) fluorescein

Correct Answer:

phenolphthalein

Explanation:

When phenol is heated with phthalic anhydride and a few drops of concentrated sulphuric acid (H₂SO₄) are added, phenolphthalein is formed. On adding excess of sodium hydroxide to this product, a pink colour is produced. This process is called phthalein fusion test.

admin:

Related Questions

  1. The atmospheric pressure is sum of the
  2. The equivalent weight of H₃PO₂, when it disproportionates into PH₃ and H₃PO₃ is
  3. A gas z is bubbled through a solution containing x⁻ and y⁻. If the reduction
  4. Chlorine is in +1 oxidation state in which of the following
  5. ‘Metals are usually not found as nitrates in their ores”. Out of the following two