| Date | November 2017 | Marks available | 2 | Reference code | 17N.3.hl.TZ0.27 |
| Level | HL | Paper | 3 | Time zone | TZ0 |
| Command term | Explain | Question number | 27 | Adapted from | N/A |
Question
Ethanol slows down the reaction time of a driver leading to traffic accidents. Explain how the concentration of ethanol in a sample of breath can be determined using a fuel cell breathalyser.
Markscheme
ethanol is oxidized «to ethanoic acid»
OR
electrons are released
current/potential proportional to concentration «of ethanol»
OR
current compared to a reference «to determine concentration»
Accept “ethanol reacts with oxygen” for M1.
Accept “voltage” for “potential”.
Examiners report
[N/A]
