electrochemistry

Anodic reacn :- 2 H₂O → O₂ + 4 H⁺ + 4e^-

Cathodic reacn :- 2 Cu ²⁺ + 4e^- → 2 Cu

NET ELECTRLYSIS REACN: - 2 Cu ²⁺ + 2H₂0 → 2 Cu + 4H⁺ +O₂

From Faraday's second law,

Wt of O₂Wt of Cu = eq wt of O₂eq wt of Cu

Therefore, wt of O₂ = (Wt of Cu) X eq wt of O₂eq wt of Cu
= 0.4 X 831.75
= 0.1008 g
= 0.00315 mol of O2
= 70 . 55 mL of O2 at STP