1. Dilute Lead Nitrate Solution:
* At the cathode (negative electrode): Hydrogen gas (H₂) is produced due to the reduction of water molecules.
* At the anode (positive electrode): Oxygen gas (O₂) is produced due to the oxidation of water molecules.
Reaction Equations:
* Cathode: 2H₂O + 2e⁻ → H₂ + 2OH⁻
* Anode: 2H₂O → O₂ + 4H⁺ + 4e⁻
Overall reaction: 2H₂O → 2H₂ + O₂
2. Concentrated Lead Nitrate Solution:
* At the cathode: Lead metal (Pb) is produced due to the reduction of lead ions (Pb²⁺).
* At the anode: Oxygen gas (O₂) is produced due to the oxidation of water molecules.
Reaction Equations:
* Cathode: Pb²⁺ + 2e⁻ → Pb
* Anode: 2H₂O → O₂ + 4H⁺ + 4e⁻
Overall reaction: Pb²⁺ + 2H₂O → Pb + O₂ + 4H⁺
Important Notes:
* Electrodes: Using inert electrodes like platinum or graphite is essential to avoid side reactions.
* Concentration: The concentration of the lead nitrate solution determines which reaction is favored at the cathode. In dilute solutions, hydrogen evolution is more favorable, while in concentrated solutions, lead deposition is favored.
In summary, the electrolysis of aqueous lead nitrate can produce:
* Hydrogen gas (H₂) and oxygen gas (O₂) in dilute solutions.
* Lead metal (Pb) and oxygen gas (O₂) in concentrated solutions.
Let me know if you'd like a more detailed explanation of any specific aspect of the process!
