Before a flame test, a nichrome wire loop is dipped in hydrochloric acid and then held in a Bunsen flame. This is repeated until the wire gives no colour to the flame.
Why is this done?
To make the flame hotter so that the colour is brighter
To remove other metal ions that would colour the flame
To make the solid stick to the wire loop more easily
To react with the metal ions so that they give a colour
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.