Electrolysis

• What is the rule for what is discharged at the cathode?

  • If the metal is less reactive than hydrogen, the metal is deposited.
  • If the metal is more reactive than hydrogen, hydrogen gas is produced.
• What is the rule for what is discharged at the anode?

  • If the solution contains a halide ion , the halogen gas is produced.
  • If there is no halide ion, oxygen gas