DP Chemistry (last assessment 2024)
Question 22N.2.hl.TZ0.2d
Date | November 2022 | Marks available | [Maximum mark: 1] | Reference code | 22N.2.hl.TZ0.2d |
Level | hl | Paper | 2 | Time zone | TZ0 |
Command term | Compare, Justify | Question number | d | Adapted from | N/A |
d.
[Maximum mark: 1]
22N.2.hl.TZ0.2d
Chloroquine is a medication used to prevent and treat malaria.
(d)
Compare, giving a reason, the length of the carbon-nitrogen bond in the ring to the length of the carbon-N1 bond.
[1]
Markscheme
«bond in ring is» shorter AND more electrons are shared
OR
«bond in ring is» shorter AND partial double/multiple bonding/bond order 1.5 ✔
Examiners report
Almost everybody identified the C−N bond in the ring as being shorter, but only about half could justify this using bond order or the resonance/delocalization that produces it. A significant number incorrectly thought the one in the ring was a double bond.
