This exam focus covers Exam Focus: Cracking 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 12 of 14 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
🎯 Exam Focus: Cracking
very-high Equation balancing (2-3 marks): Given a starting alkane and one product, deduce the other product using atom conservation.
high Bromine water test (2 marks): Describe the test, state the observation (orange → colourless) and conclusion (alkene present).
high Industrial reasons (2 marks): Explain the economic reason — converting low-value heavy fractions into high-value petrol and alkenes.
medium Higher tier — conditions (2 marks): Thermal = high T+P, catalytic = lower T+P + zeolite catalyst.
Edexcel 1CH0: Examined in Paper 2 (1CH0/2). Thermal and catalytic cracking are both tested in Edexcel 1CH0 — you must know conditions and products. In Edexcel-style questions, the command word "Suggest" appears frequently — use your chemistry knowledge to apply to an unfamiliar context.
Practice questions for Cracking (HT)
What is cracking in chemistry?
Describe the conditions used in thermal cracking and state the types of product formed.