Aniline on reaction with con.H₂SO₄ gives X. If X is heated, the product is

Aniline Reaction with Concentrated Sulfuric Acid

Aniline Reaction with Concentrated H₂SO₄

When aniline (C₆H₅NH₂) reacts with concentrated sulfuric acid (H₂SO₄), it forms anilinium hydrogensulphate (C₆H₅NH₃⁺HSO₄^-) as compound X.

C₆H₅NH₂ + H₂SO₄ → C₆H₅NH₃⁺HSO₄^- (X)

X (453-473K) → Sulphanilic acid (p-H₂NC₆H₄SO₃H)

Upon strong heating (453–473K), anilinium hydrogensulphate undergoes an internal sulfonation reaction to yield sulphanilic acid (p-aminobenzenesulfonic acid).

Summary:

• X = Anilinium hydrogensulphate
• Product after heating X = Sulphanilic acid

This reaction demonstrates the sulfonation of aniline via its salt to directly yield p-aminobenzenesulfonic acid as the major product.