A student places mineral wool soaked in liquid paraffin at one end of a hard-glass boiling tube. A solid catalyst is placed in the middle of the tube.
Which treatment should the student use to crack the liquid paraffin?
Heat the paraffin strongly and pass its vapour over the catalyst while the catalyst remains cool
Heat the catalyst strongly and occasionally warm the paraffin so that its vapour passes over the hot catalyst
Heat the catalyst strongly and warm the paraffin so that liquid paraffin flows over the hot catalyst
Heat the catalyst strongly and keep the paraffin cool so that it remains on the mineral wool
131 exam-style questions on OCR GCSE Chemistry 6.2 Organic chemistry, covering 6.2.1 Crude oil and fractional distillation, 6.2.2 Cracking and dependence on hydrocarbons, 6.2.3 Functional groups and homologous series, 6.2.4 Reactions of alkanes, alkenes and alcohols, 6.2.5 Addition polymerisation and repeat units, 6.2.6 Naturally occurring polymers, 6.2.7 Chemical cells and fuel cells, and 6.2.8 Condensation polymerisation and how to make one. Each one has a worked solution and a mark scheme showing where the marks go.