electrolysis

• Electrolysis experiment


  1. Fill beaker with chemical (copper chloride)

  2. Submerge electrodes in liquid

  3. Connect to power pack (4 volts)

  4. Positive wire to anode, negative wire to cathode

  5. Run for 5 minutes
• Copper chloride


  Contains copper ions (2+ charge) and chloride ions (Cl-)
• At positive electrode (anode)


  Chloride ions are oxidized to form chlorine gas
• At negative electrode (cathode)


  Copper ions are reduced to form copper metal
• Half equations


  Show what happens at each electrode
• Electrolysis of sodium sulfate

  1. Fill beaker with sodium sulfate

  2. Submerge electrodes

  3. Turn on circuit
• At negative electrode (cathode)


  Hydrogen gas is formed
• At positive electrode (anode)


  Oxygen gas is formed from hydroxide ions
• Balancing half equation for oxygen formation

  1. 4 hydroxide ions form oxygen gas and water

  2. Need 4 negative charges on each side to balance