DP Chemistry (last assessment 2024)
Question 17N.3.sl.TZ0.b
| Date | November 2017 | Marks available | [Maximum mark: 1] | Reference code | 17N.3.sl.TZ0.b |
| Level | sl | Paper | 3 | Time zone | TZ0 |
| Command term | Comment | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 1]
17N.3.sl.TZ0.b
One method of comparing fuels is by considering their specific energies.
A typical wood has a specific energy of 17 × 103 kJ kg–1. Comment on the usefulness of octane and wood for powering a moving vehicle, using your answer to (a).
If you did not work out an answer for (a), use 45 × 103 kJ kg–1 but this is not the correct answer.
[1]
Markscheme
wood is less useful because it requires «about three times» more mass for same energy
Accept “octane is more useful because it has higher specific energy”.
