| Date | May 2017 | Marks available | 1 | Reference code | 17M.3.hl.TZ1.19 |
| Level | HL | Paper | 3 | Time zone | TZ1 |
| Command term | Deduce | Question number | 19 | Adapted from | N/A |
Question
Dye-Sensitized Solar Cells (DSSCs) use organic dyes. Their interaction with light has some similarities to photosynthesis.
Identify two ways in which the structure of the dye shown resembles the chlorophyll molecule. Use section 35 of the data booklet.
[2]
a.
Both photosynthesis and the Grätzel cell use energy from sunlight to bring about reduction. Deduce an equation for the reduction reaction in the electrolyte of a Grätzel cell.
[1]
b.
Markscheme
delocalized bonding/conjugated bonds
contain metal atom/ion coordinated to «organic» ligand(s)
involve bonds from nitrogen to the central metal ion
[2 marks]
a.
I3– + 2e– → 3I–
Accept I2 + 2e– → 2I–.
[1 mark]
b.
Examiners report
[N/A]
a.
[N/A]
b.
