DP Chemistry (last assessment 2024)
Question 19M.2.hl.TZ1.b
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.2.hl.TZ1.b |
| Level | hl | Paper | 2 | Time zone | TZ1 |
| Command term | Explain | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 2]
19M.2.hl.TZ1.b
This question is about iron.
Explain why, when ligands bond to the iron ion causing the d-orbitals to split, the complex is coloured.
[2]
Markscheme
«frequency/wavelength of visible» light absorbed by electrons moving between d levels/orbitals [✔]
colour due to remaining frequencies
OR
complementary colour transmitted [✔]
Examiners report
This was poorly answered and showed a clear misconception and misunderstanding of the concepts. Most of the candidates failed to explain why the complex is coloured and based their answers on the emission of light energy when electrons fall back to ground state and not on light absorption by electrons moving between the split d-orbitals and complementary colour transmitted of certain frequencies.
