electrolysis

• What is electrolysis used for?

  To break down compounds using electricity
• What is the first step in the electrolysis experiment?

  Fill the beaker with 15 cm³ of chemical
• Which chemical is used first in the experiment?

  Copper chloride
• How should the electrodes be positioned in the liquid?

  Submerged but not near crocodile clips
• What voltage is recommended for this practical?

  4 volts
• What does the red wire connect to in the experiment?

  The positive terminal, the anode
• What is expected to happen when the circuit is turned on?

  A reaction will take place with chemical formation
• How long should the experiment run for?

  About five minutes
• What ions are present in copper chloride?

  Copper ions (Cu²⁺) and chloride ions (Cl⁻)
• What is observed at the positive electrode during electrolysis of copper chloride?

  Bubbles indicating gas formation
• How can chlorine ions be tested during the experiment?

  Using blue litmus paper above the anode
• What happens to the litmus paper when chlorine is present?

  It gets bleached
• What forms at the cathode during the electrolysis of copper chloride?

  Copper metal
• What is the charge of protons in the context of electrolysis?

  Protons have a 1+ charge
• How many chloride ions are needed to form a stable diatomic molecule?

  Two chloride ions
• What happens to chloride ions at the anode?

  They are oxidized to chlorine gas
• What is produced at the cathode from copper ions?

  Copper metal as a solid
• What are the half equations for the electrolysis of copper chloride?

  • At the anode: 2Cl⁻ → Cl₂ + 2e⁻ (oxidation)
  • At the cathode: Cu²⁺ + 2e⁻ → Cu (reduction)
• What is the reactivity of sodium in sodium sulfate compared to hydrogen?

  Sodium is more reactive than hydrogen
• What happens when the electrodes are placed in sodium sulfate?

  Bubbles form at both electrodes
• What gas is formed at the negative electrode during sodium sulfate electrolysis?

  Hydrogen gas
• What gas is formed at the anode during sodium sulfate electrolysis?

  Oxygen gas
• What is the source of oxygen gas at the anode?

  From hydroxide ions in water
• What type of reaction occurs at the anode during electrolysis?

  Oxidation reaction
• What additional product is formed during oxidation reactions involving hydroxide ions?

  Water
• How do you balance the charges in the electrolysis equations?

  Ensure equal negative charges on both sides
• What is the relationship between hydrogen ions and hydrogen gas in the experiment?

  Hydrogen ions gain electrons to form hydrogen gas
• What are the key points of balancing half equations in electrolysis?

  • All elements must balance
  • All charges must balance
  • Ensure correct stoichiometry