DP Chemistry (last assessment 2024)
Question 18M.3.sl.TZ2.10c.ii
| Date | May 2018 | Marks available | [Maximum mark: 1] | Reference code | 18M.3.sl.TZ2.10c.ii |
| Level | sl | Paper | 3 | Time zone | TZ2 |
| Command term | Outline | Question number | c.ii | Adapted from | N/A |
c.ii.
[Maximum mark: 1]
18M.3.sl.TZ2.10c.ii
Crude oil is a useful energy resource.
(c.ii)
The performance of hydrocarbons as fuels can be improved by catalytic reforming.
Outline how catalytic reforming increases a fuel’s octane rating.
[1]
Markscheme
produces more branched chain hydrocarbons «with higher octane rating»
OR
produces aromatics «which have higher octane rating»
OR
produces cyclohexanes «which have higher octane rating»
Accept “increase branches”.
Do not accept “produces benzene”.
Do not penalize for “benzene” if penalty applied in 2.b.iii.
Accept “produces cyclic structures”.
[1 mark]
