Study the reaction scheme shown below and identify the reactants A , B and C .

A → Concentrated Sulphuric Acid (conc. H₂SO₄)
B → Acetic acid (CH₃COOH)
C → Oxygen (O₂)

Explanation

• Ethanol ⟶ Ethene (with reactant A): This is dehydration of ethanol. A is concentrated sulphuric acid (conc. H₂SO₄) at 170°C.
  C₂H₅OH $\xrightarrow[170^{\circ}\text{C}]{\text{conc. H}_2\text{SO}_4}$ C₂H₄ + H₂O

• Ethanol ⟶ Ethyl acetate (with reactant B): This is esterification. B is acetic acid (CH₃COOH) in the presence of conc. H₂SO₄ (acts as a catalyst).
  C₂H₅OH + CH₃COOH $\xrightarrow{\text{conc. H}_2\text{SO}_4}$ CH₃COOC₂H₅ + H₂O

• Ethanol ⟶ Carbon dioxide + Water (with reactant C): This is combustion. C is oxygen (O₂).
  C₂H₅OH + 3O₂ ⟶ 2CO₂ + 3H₂O

Hence, A = Concentrated H₂SO₄, B = Acetic acid (CH₃COOH), and C = Oxygen (O₂).