Cracking

IGCSE Edexcel Chemistry
4.17-4.18 Cracking of hydrocarbons
Key Concept: Cracking breaks long-chain alkanes into shorter alkanes and alkenes using heat and a catalyst.

Section A: Process

1. Describe the conditions needed for catalytic cracking. [3]
2. Explain why cracking is necessary. [2]

Section B: Products

3. Complete the cracking equation: C10H22 -> C6H14 + ____. [2]
4. Name the type of hydrocarbon produced with a double bond. [1]

Total marks: 8

Mark Scheme

1. High temperature (about 600-700 C) and a catalyst such as silica/alumina [3]
2. To match supply with demand; short-chain fuels and alkenes are more useful [2]
3. C4H8 [2]
4. Alkene [1]