| Date | May 2009 | Marks available | 1 | Reference code | 09M.3.sl.TZ2.A1 |
| Level | SL | Paper | 3 | Time zone | TZ2 |
| Command term | Calculate | Question number | A1 | Adapted from | N/A |
Question
The following diagram represents a thin-layer chromatogram of an amino acid.
Calculate the \({R_{\text{f}}}\) of the amino acid.
Markscheme
\({R_{\text{f}}} = \frac{{40{\text{ (mm)}}}}{{46{\text{ (mm)}}}} = 0.87\);
Allow 0.86 to 0.88.
No mark if \({R_{\text{f}}}\) has units.
Examiners report
There were difficulties in the calculation of \({R_{\text{f}}}\), some candidates did not seem to know what it means, others what to measure.
Syllabus sections
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