Anode/Cathode in a fuel cell: "AN OX, RED CAT" — ANnode = OXidation; REDuction at CAThode.
Fuel cell half-equations:
- Anode (loss of electrons): H₂ → 2H⁺ + 2e⁻ — hydrogen splits and leaves electrons behind
- Cathode (gain of electrons): oxygen grabs the electrons and pairs with H⁺ to make water
Reactivity difference = voltage: Think of a see-saw — the bigger the difference between two metals on the reactivity series, the bigger the "tilt" (voltage).
Battery types mnemonic — NRA: Non-rechargeable (alkaline) → Rechargeable (lithium-ion) → Accumulator (lead-acid)
This memory aid covers Memory Aids within Fuel Cells for GCSE Chemistry. Revise Fuel Cells in Energy Changes for GCSE Chemistry with 5 exam-style questions and 6 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 10 of 13 in this topic. Use it for quick recall, then test yourself straight afterwards so the memory aid becomes usable in an answer.
Practice questions for Fuel Cells
A simple electrochemical cell is made by placing two different metal electrodes into an electrolyte. Which statement correctly describes what affects the voltage produced?
Compare a non-rechargeable alkaline battery with a rechargeable lithium-ion battery. Give one advantage and one disadvantage of the rechargeable battery.