Electolysis

• What is electrolysis?

  Electrolysis is the process of decomposing an ionic compound using electricity.
• What is an electrolyte?

  A molten or aqueous ionic compound that conducts electricity.
• What is the anode?

  The positive electrode where oxidation occurs.
• What is the cathode?

  The negative electrode where reduction occurs.
• What does OIL RIG stand for?

  Oxidation Is Loss (of electrons), Reduction Is Gain (of electrons).
• What is produced at the cathode during the electrolysis of water?

  Hydrogen gas (2H⁺ + 2e⁻ → H₂).
• What is produced at the anode during the electrolysis of water?

  Oxygen gas (4OH⁻ → O₂ + 2H₂O + 4e⁻).
• In water electrolysis, why is hydrogen volume double that of oxygen?

  Because for every 2 molecules of hydrogen, only 1 molecule of oxygen is produced.
• What happens at the cathode during electrolysis of molten ionic compounds?

  Metal cations gain electrons to form metal atoms.
• What happens at the anode during electrolysis of molten ionic compounds?

  Non-metal anions lose electrons to form non-metal elements.
• What is an example of electrolysis of a molten compound?

  Pb²⁺ + 2e⁻ → Pb and 2Br⁻ → Br₂ + 2e⁻.
• What ions are present in aqueous solutions affecting electrolysis?

  H⁺ and OH⁻ ions from water.
• What is produced at the cathode if the metal is less reactive than hydrogen?

  The metal is deposited.
• What is produced at the cathode if the metal is more reactive than hydrogen?

  Hydrogen gas is produced.
• What is produced at the anode if halide ions are present?

  The corresponding halogen (e.g., Cl₂, Br₂).
• What is produced at the anode if no halide ions are present?

  Oxygen gas from OH⁻ ions.
• How do you investigate electrolysis?

  Set up a cell, connect to power, observe electrodes, collect/test gases.
• What gas relights a glowing splint?

  Oxygen.
• What gas gives a squeaky pop with a lit splint?

  Hydrogen.
• What is electroplating?

  Using electrolysis to deposit a thin layer of metal onto an object.
• In electroplating, what is the cathode?

  The object to be plated.
• In electroplating, what is the anode?

  The metal used for plating.
• What is the electrolyte in electroplating?

  A solution containing ions of the plating metal.
• What is a common setup for silver plating?

  Silver anode, object cathode, silver nitrate electrolyte.
• What mnemonic helps remember oxidation/reduction?

  OIL RIG: Oxidation Is Loss, Reduction Is Gain.
• How can you determine the product at each electrode?

  Identify ions and use the reactivity series to predict outcomes.