Assertion: The product of electrolysis of CuSO₄ solution using inert electrode at anode is O₂ and Cu at cathode.

Reason: pH of solution decreases during electrolysis. 

Assertion and Reason both are correct statements and reason is the correct explanation for assertion.

CuSO₄ solution using inert electrodes.

CuSO₄ ⇔ Cu²⁺ + SO₄^2-

H₂O ⇔ H⁺ + OH^- 

At anode: 2OH^- → H₂O + \(\frac{1}{2}\)O₂ + 2e^-

At cathode: Cu²⁺ + 2e^- → Cu 

H⁺ interacts with SO₄^2- to form H₂SO₄. So, pH of solution decreases during electrolysis.