DP Chemistry (last assessment 2024)
Question 18M.3.hl.TZ1.a
Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.3.hl.TZ1.a |
Level | hl | Paper | 3 | Time zone | TZ1 |
Command term | Outline | Question number | a | Adapted from | N/A |
a.
[Maximum mark: 2]
18M.3.hl.TZ1.a
Anthocyanins are naturally occurring plant pigments. Depending on the solution pH, they can exist as quinoidal bases or flavylium cations as shown in section 35 of the data booklet.
Outline why anthocyanins are coloured.
[2]
Markscheme
highly conjugated systems
OR
alternating single and double bonds
OR
many delocalized electrons
electron transitions occur when visible light is absorbed
[2 marks]
