DP Chemistry (last assessment 2024)
Question 18M.3.hl.TZ2.13c
| Date | May 2018 | Marks available | [Maximum mark: 3] | Reference code | 18M.3.hl.TZ2.13c |
| Level | hl | Paper | 3 | Time zone | TZ2 |
| Command term | Determine | Question number | c | Adapted from | N/A |
c.
[Maximum mark: 3]
18M.3.hl.TZ2.13c
Crude oil is a useful energy resource.
(c)
Fuel cells have a higher thermodynamic efficiency than octane. The following table gives some information on a direct methanol fuel cell.
Determine the thermodynamic efficiency of a methanol fuel cell operating at 0.576 V.
Use sections 1 and 2 of the data booklet.
[3]
Markscheme
n = 6
«ΔGΘ = –nFEΘ = 6 mol × 96 500 C mol–1 × 0.576 V =» –333 504 J/–334 kJ
«Efficiency = =» 0.459/45.9%
Award [3] for correct final answer.
[3 marks]
