Question

Give a balanced equation by the partial equation method, [steps are given below].

Oxidation of Lead [II] Sulphide by Ozone

1. Ozone first decomposes to give molecular oxygen & nascent oxygen.
2. Nascent oxygen then oxidises lead [II] sulphide to lead [II] sulphate. 

Answer 1

1. Ozone decomposes to O₂ (molecular) and nascent oxygen.
2. Nascent oxygen oxidises Pb [II] sulphide to Lead [II] sulphate and needs 4 atoms of oxygen to form sulphate. Hence 1^st equation must be multiplied by 4. Cancelling 4 atoms of oxygen from both sides and adding.

           O₃ → O₂ + [O] × 4
           PbS + 4O → PbSO₄          
           PbS + 4O₃ → PbSO₄ + 4O₂