DP Chemistry (first assessment 2025)
Question 23M.2.HL.TZ2.13a
Date | May 2023 | Marks available | [Maximum mark: 2] | Reference code | 23M.2.HL.TZ2.13a |
Level | HL | Paper | 2 | Time zone | TZ2 |
Command term | Explain | Question number | a | Adapted from | N/A |
a.
[Maximum mark: 2]
23M.2.HL.TZ2.13a
(a)
Explain in terms of its structure, why β-carotene appears orange in visible white light. Refer to section 17 of the data booklet.
[2]
Markscheme
contains many/multiple conjugated «carbon–carbon/C=C» double bonds
OR
extended system of delocalized electrons ✓
absorbs blue
OR
complementary to orange «light» ✓
M1 requires the concept of many or multiple conjugated double bonds in structure for mark.
Do not accept either “conjugation” OR “double bonds” alone for M1.
