Core Concepts (Target: 'S' Pass)

• Define: What is an electrochemical cell (e.g., a battery)?

• Define: What is electrolysis?

• Identify: In a simple cell with zinc and copper electrodes, which one is the negative terminal?

• Define: What is oxidation in terms of electrons?

• List: What two conditions are necessary for the rusting of iron?

• Name: What is the term for coating an object with a metal using electrolysis?

Understanding & Application (Target: 'C' Pass)

• Explain: In the electrolysis of aqueous copper(II) sulfate using inert carbon electrodes, what is formed at the cathode and what is formed at the anode?

• Describe: Explain how coating iron with a layer of paint prevents it from rusting.

• Apply: To electroplate an iron spoon with silver, what would you use for the anode, the cathode, and the electrolyte?

• Compare: What is the key difference between an electrochemical cell and an electrolytic cell in terms of energy conversion?

• Write: Write the half-reaction that occurs at the anode in a simple Zn/Cu cell.

Analysis & Higher-Order Thinking (Target: 'B' / 'A' Pass)

• Analyse: A galvanized iron sheet is coated with zinc. Explain, with reference to the reactivity series and electrochemical principles, why the iron is still protected from rust even if the zinc coating is scratched.

• Justify: Explain why solid sodium chloride does not conduct electricity, but molten or aqueous sodium chloride does.

• Synthesize: During the electrolysis of concentrated aqueous sodium chloride, hydrogen gas is produced at the cathode instead of sodium metal. Explain why, considering the reactivity of the elements involved.

• Apply: Write the balanced half-equations for the reactions occurring at the anode and cathode during the electrolysis of molten sodium chloride.

O/L Exam Tip: For any cell (electrochemical or electrolytic), remember "AN OX" (Anode is Oxidation) and "RED CAT" (Reduction at Cathode). Be clear on which electrode is positive and which is negative in each type of cell.