DP Chemistry (first assessment 2025)
Question 19M.1A.HL.TZ2.6
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.1A.HL.TZ2.6 |
| Level | HL | Paper | 1A | Time zone | TZ2 |
| Command term | Question number | 6 | Adapted from | N/A |
6.
[Maximum mark: 1]
19M.1A.HL.TZ2.6
How is colour produced in transition metal complexes?
A. Light is absorbed when electrons are promoted between split d-orbitals.
B. Light is emitted when electrons fall between split d-orbitals.
C. Light is absorbed when electrons escape from the complex.
D. Light is emitted when the complex returns to ground state.
[1]
Markscheme
A
Examiners report
69 % of the candidates understood how colour is produced in transition metal complexes. The most commonly chosen distractor was B, which also recognized the involvement of the split d-orbitals, however stated that colour is produced when light is emitted when electrons fall between split d-orbitals.
Syllabus sections
Structure 3. Classification of matter » Structure 3.1—The periodic table: Classification of elements » Structure 3.1.10—Transition element complexes are coloured due to the absorption of light when an electron is promoted between the orbitals in the split d-sublevels. The colour absorbed is complementary to the colour observed. Apply the colour wheel to deduce the wavelengths and frequencies of light absorbed and/or observed.