Which of the following is formed when maltose reacts with concentrated tetraoxosulphate (VI) acid ?

 Which of the following is formed when maltose reacts with concentrated tetraoxosulphate (VI) acid ?

• A. Carbon (IV) oxide
• B. Coal tar
• C. Charcoal
• D. Toxic fumes

✅ Correct Answer: Carbon (a black residue).

When maltose (a reducing disaccharide made of two glucose units) reacts with concentrated tetraoxosulphate(VI) acid (H₂SO₄), it does not undergo normal hydrolysis.

Instead, conc. H₂SO₄ acts as a powerful dehydrating agent.

• It removes water ($H₂O$) from the sugar.

• What remains is carbon (C), usually seen as a black mass.

Jamb 1990 past question 49