This question is about hydrocarbons and chemical cracking.
Alkanes are saturated hydrocarbons with a general molecular formula of CnH2n+2C_nH_{2n+2}CnH2n+2. Which of the following molecular formulas represents an alkane? (a) C4H8C_4H_8C4H8 (b) C6H12C_6H_{12}C6H12 (c) C8H18C_8H_{18}C8H18 (d) C10H20C_{10}H_{20}C10H20
Describe the typical reaction conditions necessary to carry out the catalytic cracking of long-chain hydrocarbons.
Complete the following equation for the cracking of octadecane (C18H38C_{18}H_{38}C18H38):
C18H38→C13H28+____ C_{18}H_{38} \rightarrow C_{13}H_{28} + \text{\_\_\_\_} C18H38→C13H28+____Explain why the reactant C18H38C_{18}H_{38}C18H38 has a significantly higher boiling point than the product C13H28C_{13}H_{28}C13H28.
12 exam-style questions on AQA GCSE Chemistry 7.1 Carbon compounds as fuels and feedstock, covering 7.1.1 Crude oil, hydrocarbons and alkanes, 7.1.2 Fractional distillation and petrochemicals, 7.1.3 Properties of hydrocarbons, and 7.1.4 Cracking and alkenes. Each one has a worked solution and a mark scheme showing where the marks go.