DP Chemistry (last assessment 2024)
Question 19N.3.hl.TZ0.20d(i)
| Date | November 2019 | Marks available | [Maximum mark: 3] | Reference code | 19N.3.hl.TZ0.20d(i) |
| Level | hl | Paper | 3 | Time zone | TZ0 |
| Command term | Outline | Question number | d(i) | Adapted from | N/A |
d(i).
[Maximum mark: 3]
19N.3.hl.TZ0.20d(i)
A proton-exchange membrane (PEM) fuel cell uses pure hydrogen gas as the fuel and a proton exchange membrane as the electrolyte.
A dye-sensitized solar cell (DSSC) uses light energy to produce electricity.
(d(i))
Outline the functions of the dye, TiO2 and the electrolyte in the operation of the DSSC.
Dye:
TiO2:
Electrolyte:
[3]
Markscheme
Dye:
absorbs photons/light
OR
releases electrons ✔
TiO2:
conducts current/electricity
OR
semiconductor ✔
Electrolyte:
reduces/regenerates «the oxidized» dye ✔
