Crude oil is a complex mixture of hydrocarbons that is separated into useful fractions using fractional distillation.
Which statement correctly describes the properties of these fractions or the separation process?
Fractions collected near the top of the column are highly volatile and have higher viscosities than fractions collected near the bottom.
Molecules in the fractions collected near the bottom of the column have larger surface areas, leading to stronger temporary dipole-induced dipole (London) forces between molecules.
Fractional distillation is a chemical process during which covalent bonds within the hydrocarbon chains are broken and reformed.
The refinery gas fraction obtained at the top of the column consists mainly of short-chain, unsaturated hydrocarbons such as ethene.
Practise Edexcel GCSE Chemistry Fuels with exam-style questions for Foundation and Higher tier. 100 questions, matched to the Edexcel GCSE Chemistry (1CH0) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.