A technician investigates an unexpected result when testing solid Q, which contains one type of metal ion.
| Trial | Treatment of nichrome wire loop | Flame colour |
|---|---|---|
| 1 | Cleaned before testing Q | Red |
| 2 | Used to test a sodium compound, then used for Q without cleaning | Yellow-orange |
The technician has simplified reference spectra measured under the same conditions.
| Metal ion | Lines in emission spectrum (nm) |
|---|---|
| Lithium | 610, 671 |
| Sodium | 589 |
Explain why the flame colours in trials 1 and 2 are different.
Give the wavelengths that would be detected if the light from the flame in trial 2 were analysed using flame emission spectroscopy.
107 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.