During the industrial refining of crude oil, larger, less useful alkane molecules are broken down into shorter, more valuable hydrocarbons through catalytic cracking.
The equation below represents the thermal cracking of a single molecule of pentadecane to form one molecule of hexene and one molecule of an unidentified hydrocarbon product:
C15H32→C6H12+CxHy \text{C}_{15}\text{H}_{32} \rightarrow \text{C}_6\text{H}_{12} + \text{C}_x\text{H}_y C15H32→C6H12+CxHyDetermine the values of x x\,x and y y\,y in this equation.
130 exam-style questions on Edexcel GCSE Chemistry 9.1 Fuels, covering 9.1.1 Hydrocarbons and crude oil, 9.1.2 Fractional distillation of crude oil and its fractions, 9.1.3 The alkanes as a homologous series, 9.1.4 Complete and incomplete combustion, 9.1.5 Pollutants from burning fuels, 9.1.6 Hydrogen as a fuel and non-renewable fossil fuels, and 9.1.7 Cracking of larger alkanes. Each one has a worked solution and a mark scheme showing where the marks go.