A forensic scientist uses mass spectrometry to test a powder. The table shows the main peaks for three known drugs, P, Q and R, and for the powder.
| Substance | Mass-to-charge ratios of main peaks |
|---|---|
| Drug P | 43, 58, 72, 86 |
| Drug Q | 44, 91, 119, 135 |
| Drug R | 58, 91, 148 |
| Powder | 43, 44, 58, 72, 86, 91, 119, 135 |
Which drugs are in the powder?
P only
Q only
P and Q
Q and R
52 exam-style questions on OCR GCSE Chemistry 4.2 Identifying the products of chemical reactions, covering 4.2.1 Tests to identify gases, 4.2.2 Tests for aqueous ions and flame tests, and 4.2.3 Instrumental methods of analysis. Each one has a worked solution and a mark scheme showing where the marks go.