DP Chemistry (last assessment 2024)
Question 18N.3.sl.TZ0.10b.ii
| Date | November 2018 | Marks available | [Maximum mark: 1] | Reference code | 18N.3.sl.TZ0.10b.ii |
| Level | sl | Paper | 3 | Time zone | TZ0 |
| Command term | Comment | Question number | b.ii | Adapted from | N/A |
b.ii.
[Maximum mark: 1]
18N.3.sl.TZ0.10b.ii
Coal can be converted to clean-burning synthetic natural gas.
Automobile companies use hydrogen as an alternative to fossil fuels. Some properties of fuels are shown.
(b.ii)
Comment on the specific energies of hydrogen and methane.
[1]
Markscheme
«» hydrogen/H2 produces 2.6 times/more than twice the energy of methane/CH4 «per mass/g»
OR
less mass of hydrogen/H2 required «to produce same amount of energy»
OR
hydrogen/H2 more energy efficient ✔
Accept “hydrogen/H2 produces «nearly» three times more energy than methane/CH4 «per mass/g»”.
