A refinery engineer is checking which hydrocarbon is collected from a particular tray in a fractionating column. The temperatures at four positions in the column are shown.
| Position in column | Temperature (∘C^\circ\mathrm{C}∘C) |
|---|---|
| Bottom tray | 300 |
| Tray below the outlet | 230 |
| Outlet tray | 160 |
| Tray above the outlet | 90 |
The boiling points of four hydrocarbons are shown in the table.
| Hydrocarbon | Boiling point (∘C^\circ\mathrm{C}∘C) |
|---|---|
| P | 75 |
| Q | 125 |
| R | 180 |
| S | 250 |
Which hydrocarbon is collected from the outlet tray?
Hydrocarbon Q
Hydrocarbon S
Hydrocarbon R
Hydrocarbon P
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.