This exam focus covers Exam Focus within Electrolysis of Molten Compounds for GCSE Chemistry. Revise Electrolysis of Molten Compounds in Electrolysis for GCSE Chemistry with 21 exam-style questions and 14 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 9 of 11 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
🎯 Exam Focus
Frequently Examined
Molten electrolysis is examined with both written explanations and half equations. Key areas:
- Predicting products — state the metal at cathode and non-metal at anode with justification
- Explaining WHY ions move — always use the word "attracted" and refer to opposite charges
- Writing half equations — must balance atoms AND charges; include electrons
- Explaining conductivity — solid does not conduct because ions cannot move; molten does conduct because ions are free
- Identifying oxidation and reduction — which electrode, which type of ion, which process
→ See also: Required Practical: Electrolysis of Aqueous Solutions — extends these principles to aqueous solutions with competing ions.
Edexcel 1CH0: Examined in Paper 1 (1CH0/1). Questions on molten ionic compounds test electrode half-equations — Edexcel requires you to write half-equations at cathode and anode. In Edexcel-style questions, the command word "Suggest" appears frequently — use your chemistry knowledge to apply to an unfamiliar context.
Quick Check: What products form when molten sodium chloride (NaCl) is electrolysed? Write a half equation for the cathode.
Sodium metal (Na) forms at the cathode, and chlorine gas (Cl₂) forms at the anode. Cathode half equation: Na⁺ + e⁻ → Na. (Sodium ions gain one electron each and are reduced to sodium metal.)
Practice questions for Electrolysis of Molten Compounds
Which condition is required for electrolysis to occur with an ionic compound?
State the products formed at each electrode when molten lead bromide (PbBr₂) is electrolysed.