As part of a life-cycle assessment of alternative aviation fuels, a chemist investigates the catalytic cracking of bio-dodecane (C12H26\text{C}_{12}\text{H}_{26}C12H26), a saturated constituent of bio-paraffin. The cracking of one molecule of bio-dodecane yields exactly one molecule of propene, one molecule of but-1-ene, and a single molecule of product XXX.
Which of the following correctly identifies the molecular formula of product X X\,X and states whether it is saturated or unsaturated?
C5H10\text{C}_5\text{H}_{10}C5H10, which is unsaturated
C5H10\text{C}_5\text{H}_{10}C5H10, which is saturated
C5H12\text{C}_5\text{H}_{12}C5H12, which is saturated
C5H12\text{C}_5\text{H}_{12}C5H12, which is unsaturated
83 exam-style questions on OCR GCSE Chemistry Organic chemistry. Each one has a worked solution and a mark scheme showing where the marks go.