Ionic Dissociation and Hydrolysis in Aqueous CuSO₄

Steps:

• Copper(II) sulfate (CuSO₄) dissolves in water and dissociates into Cu²⁺ and SO₄²⁻ ions.
• The Cu²⁺ ions undergo hydrolysis: Cu²⁺ + H₂O ⇌ CuOH⁺ + H⁺.
• This reaction produces hydrogen ions (H⁺) in solution.
• Therefore, the positive ions present are Cu²⁺ and H⁺.

Why B is correct:

• Aqueous copper(II) sulfate is acidic due to hydrolysis of Cu²⁺, which releases H⁺ ions as per the equilibrium Cu(H₂O)₆²⁺ + H₂O ⇌ Cu(H₂O)₅OH⁺ + H₃O⁺.

Why the others are wrong:

• A: Excludes H⁺ ions produced by hydrolysis of Cu²⁺.
• C: Omits Cu²⁺, the primary cation from dissociation.
• D: Lists anions (sulfate and hydroxide), not positive ions.

Final answer: B