DP Chemistry (last assessment 2024)
Question 19M.3.hl.TZ2.25b
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.hl.TZ2.25b |
| Level | hl | Paper | 3 | Time zone | TZ2 |
| Command term | Outline | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 2]
19M.3.hl.TZ2.25b
Taxol is a drug that was once obtained from yew trees and is now produced using chiral auxiliaries.
(b)
Outline the operation of a polarimeter used to distinguish between enantiomers.
[2]
Markscheme
Any two of:
«plane-» polarized light
OR
light passes through polarizer/polarizing filter [✔]
enantiomers rotate plane of «plane-» polarized light «by equal angles» in opposite directions [✔]
measure angle/direction of rotation [✔]
Examiners report
The operation of a polarimeter to distinguish between enantiomers was generally well handled by the candidates while some missed stating to measure the angle/direction of rotation.
