This deep dive covers Equipment and Method within Flame Tests for GCSE Chemistry. Revise Flame Tests in Chemical Analysis for GCSE Chemistry with 22 exam-style questions and 15 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 4 of 13 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
🧪 Equipment and Method
Equipment Needed
- Bunsen burner — provides the heat energy
- Nichrome wire loop — holds the sample (nichrome is unreactive and melts at very high temperature)
- Dilute hydrochloric acid (HCl) — cleans the wire between tests
- Sample of metal compound — the substance to be identified
- Safety goggles — essential eye protection
Why Nichrome Wire, Not Iron Wire?
The flame test wire must be nichrome (a nickel-chromium alloy) or platinum — never iron wire. Iron wire is unsuitable because iron oxidises in the flame and produces its own orange-brown colour, which contaminates the result and masks the true flame colour of the sample. Nichrome is chosen because it is unreactive, has a very high melting point, and does not produce a visible flame colour of its own. Some older textbooks refer to a "wire loop" without specifying the material — if asked in an exam, always state nichrome wire.
Step-by-Step Method
- Dip the nichrome wire loop in dilute HCl
- Hold in the blue Bunsen flame until no colour is seen (wire is clean)
- Dip the clean wire in HCl again, then into the sample
- Hold the wire with sample in the blue Bunsen flame
- Observe and record the flame colour immediately
- Clean the wire thoroughly before testing the next sample
Important: Use the blue flame (fully open air hole) — it is the hottest part of the Bunsen flame and gives the clearest results.
Practice questions for Flame Tests
Which type of wire is used to carry out a flame test?
Explain why different metal ions produce different colours in flame tests.