This question is about hydrocarbons and industrial cracking processes.
Alkenes are unsaturated hydrocarbons with the general molecular formula CnH2nC_nH_{2n}CnH2n. Which of the following molecular formulas represents an alkene?
(a) C4H10C_4H_{10}C4H10 (b) C6H14C_6H_{14}C6H14 (c) C8H16C_8H_{16}C8H16 (d) C10H22C_{10}H_{22}C10H22
Describe the typical reaction conditions required specifically for the catalytic cracking of long-chain hydrocarbons.
Complete the following equation for the industrial cracking of octadecane (C18H38C_{18}H_{38}C18H38):
C18H38→C12H26+2 ____ C_{18}H_{38} \rightarrow C_{12}H_{26} + 2\,\text{\_\_\_\_} C18H38→C12H26+2____Explain, in terms of intermolecular forces, why the reactant C18H38C_{18}H_{38}C18H38 has a significantly higher boiling point than the product C12H26C_{12}H_{26}C12H26.
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.