A computer simulation is used to plan production at a petrochemical works.
The stock change is measured after all customer orders for the week have been processed. A positive stock change shows a surplus and a negative stock change shows a shortage.
| Fraction | Typical number of carbon atoms in each molecule | Stock change (tonnes) |
|---|---|---|
| LPG | 3 | 0 |
| Petrol | 8 | -14 |
| Diesel oil | 16 | +18 |
| Bitumen | 35 | -4 |
Which instruction should the simulation give?
Crack diesel oil to increase petrol.
Crack bitumen to increase LPG.
Crack LPG to increase petrol.
Crack petrol to increase diesel oil.
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.