electrolysis

• What is electrolysis?

  Decomposition of ionic compounds using electricity
• What state must ionic compounds be in for electrolysis to occur?

  Must be molten or in aqueous solution
• What are the two types of electrodes in electrolysis?

  Positive electrode (anode) and negative electrode (cathode)
• What is the role of the electrolyte in electrolysis?

  It allows ions to move freely and carry charge
• What happens during the electrolysis of molten compounds?

  • Electrical current passes through substance
  • Causes oxidation at anode and reduction at cathode
  • Ions must be free to move
  • Used to obtain pure metals from compounds
• Why can electrolysis also be carried out on solutions?

  Dissolved ions are free to move in the mixture
• In the electrolysis of sodium chloride solution, which ions move to the cathode?

  H+ ions move to the cathode
• What is the reaction that occurs at the cathode during the electrolysis of sodium chloride solution?

  2H+(aq) + 2e− → H2(g)
• What happens to the more reactive cation during electrolysis of solutions?

  It remains in solution
• What happens to halide ions during electrolysis?

  • Halide ions (F−, Cl−, Br−) are oxidized at the anode
  • If anion isn't a halide, oxygen is oxidized instead
  • Oxygen is produced in that case