Question 18N.3.hl.TZ0.23
| Date | November 2018 | Marks available | [Maximum mark: 3] | Reference code | 18N.3.hl.TZ0.23 |
| Level | hl | Paper | 3 | Time zone | TZ0 |
| Command term | Outline, State | Question number | 23 | Adapted from | N/A |
Scientists have developed various analytical techniques.
State an analytical technique used to separate anabolic steroids from other compounds in an athlete’s urine or blood.
[1]
gas chromatography/GC
OR
high performance liquid chromatography/HPLC ✔
Accept “chromatography”, “TLC/thin-layer chromatography”, “paper chromatography” OR “extraction”.
Do not accept just “mass spectrometry/MS” but do not penalize any reference to MS with HPLC or GC (eg GC-MS).
Ethanol in breath can be detected by a redox reaction. Outline this method of detection. An equation is not required.
[2]
ALTERNATIVE 1:
Any two of:
«blow through tube of» acidified «orange» potassium dichromate(VI)/K2Cr2O7/dichromate/Cr2O72– ✔
Cr(VI)/Cr6+/Cr2O72– reduced to Cr(III)/Cr3+✔
colour changes «from orange» to green
OR
colour change is monitored ✔
ALTERNATIVE 2:
oxygen reduced to water
OR
ethanol oxidized to ethanoic/acetic acid ✔
current measured ✔
Accept “ethanol oxidized to ethanal/acetaldehyde”.
