3.3 Electrolysis

• Electrolysis requires electricity to occur.


  True
• Ions can be positively charged (cations) or negatively charged (anions).


  True
• Give an example of an electrolyte.

  NaCl
• What are electrolytes defined as?

  Ionic compounds
• What type of reaction occurs at the cathode?

  Reduction
• What happens to cations when they reach the cathode?

  Reduction
• Other chemical reactions are driven by chemical potential.
• What happens to electrons at the cathode during reduction?

  They are gained
• What is an example of a reduction reaction at the cathode?

  Na⁺ + e⁻ → Na
• What is oxidation at the anode defined as?

  Losing electrons by anions
• What gas is formed when chloride ions lose electrons at the anode?

  Chlorine gas
• Other chemical reactions are driven by chemical
• What are positively charged ions called?

  Cations
• What type of reaction occurs at the cathode?

  Reduction
• Reduction at the cathode involves cations gaining electrons to form neutral atoms.

  True
• The general chemical equation for reduction is Cation⁺ + e⁻ → Neutral Atom
• Oxidation at the anode involves anions losing electrons.

  True
• Order the key aspects of oxidation reactions at the anode:

  1️⃣ Losing electrons by anions |

  
  

  2️⃣ Involves anions (negative ions) |

  
  

  3️⃣ Electron transfer: Loses electrons |

  
  

  4️⃣ Reaction type: Oxidation |
• In aqueous electrolysis, oxygen gas is always formed at the anode.

  False
• What is produced at the cathode when molten sodium chloride (NaCl) is electrolyzed?

  Sodium metal (Na)
• What is electroplating used for?

  Coating metal surfaces
• What is electrolysis?

  Decomposition by electrical current
• What is an electrolyte?

  Ionic compound that conducts electricity
• Electrolytes contain free-moving ions that carry an electric current
• Electrolytes conduct electricity when molten or dissolved in water
• Arrange the steps in an electrolytic cell in the correct order:

  1️⃣ Oxidation occurs at the anode

  2️⃣ Reduction occurs at the cathode
• During electrolysis, cations move towards the cathode.


  True
• What is the process of electrolysis used for?

  Decomposition of ionic compounds
• Match the term with its example:

  Ion ↔️ Na⁺

  Electrolyte ↔️ NaCl
• Cations gain electrons at the cathode during reduction.


  True
• Oxidation at the anode involves anions losing electrons.

  True
• Oxidation at the anode is essential for electrolysis because it enables the breakdown of ionic compounds.

  True
• What is electrolysis used to drive chemical reactions that would not normally occur?

  Electricity
• The power source in electrolysis supplies the electrical current needed to decompose the ionic electrolyte.


  True
• Match the ion type with its property:

  Cations ↔️ Positively charged

  Anions ↔️ Negatively charged
• What is the charge of the electrode where anions move during electrolysis?

  Positive
• Reduction involves cations gaining electrons at the cathode.

  True
• Order the key aspects of reduction reactions at the cathode:

  1️⃣ Gaining electrons by cations |

  
  

  2️⃣ Involves cations (positive ions) |

  
  

  3️⃣ Electron transfer: Gains electrons |

  
  

  4️⃣ Reaction type: Reduction |
• The general chemical equation for oxidation is Anion⁻ → Neutral Atom + e⁻
• What gas is formed at the cathode during aqueous electrolysis if the metal ions are less reactive than hydrogen?

  Hydrogen gas (H₂)