This memory aid covers Memory Aid: CRACK a Big Biscuit within Cracking (HT) for GCSE Chemistry. Revise Cracking (HT) in Organic Chemistry for GCSE Chemistry with 24 exam-style questions and 15 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 11 of 14 in this topic. Use it for quick recall, then test yourself straight afterwards so the memory aid becomes usable in an answer.
🧠 Memory Aid: CRACK a Big Biscuit
Think of cracking like breaking a long biscuit into smaller pieces:
- Big biscuit = long alkane (e.g., C₁₀H₂₂)
- Break it = crack it with heat/catalyst
- Smaller pieces = shorter alkane + alkene
- More useful = petrol + polymer material
For the bromine water test memory: Orange → Colourless = Alkene present. Think of a traffic light going from orange (stop) to nothing (clear) — the alkene has "cleared" the colour.
Equation check trick: Add up all carbons on the left, check they match on the right. Then do the same for hydrogens. If they balance, you've cracked it correctly!
Practice questions for Cracking (HT)
What is cracking in chemistry?
Describe the conditions used in thermal cracking and state the types of product formed.