| Date | November 2009 | Marks available | 2 | Reference code | 09N.3.sl.TZ0.E2 |
| Level | SL | Paper | 3 | Time zone | TZ0 |
| Command term | State | Question number | E2 | Adapted from | N/A |
Question
The biochemical oxygen demand (BOD) is a measure of water pollution.
State what is meant by the term biochemical oxygen demand (BOD).
Markscheme
amount of oxygen needed to decompose organic matter (in water sample);
in a specified time/five days / at a specified temperature/ 20 °C;
Examiners report
Most candidates knew the meaning of BOD.
Syllabus sections
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