ChemistryChapter 18: Qualitative Analysis
Flame Tests
A flame test is a qualitative test for some metal ions.
What this grid covers
A flame test is a qualitative test for some metal ions. A clean nichrome wire, dipped in concentrated HCl to clean it, then in the sample, is held in a roaring Bunsen flame. The colour is a clue, not a full proof if sodium yellow is also present.
School colours to learn:
| n | Ion | Flame colour | Watch-out |
|---|---|---|---|
| 1. Na+ | Persistent yellow-orange | Masks other colours | |
| 2. K+ | Lilac (view through blue glass if Na is present) | Easy to miss beside sodium | |
| 3. Ca2+ | Brick red | Not as lasting as sodium | |
| 4. Ba2+ | Apple green | Do not confuse with copper | |
| 5. Cu2+ | Blue-green | Often from copper salts | |
| 6. Li+ | Crimson red | Different from calcium's brick red |
Explanation
Clean the wire until it gives no colour of its own. A dirty wire that still has sodium will 'prove' every sample is sodium.
In simple words
Flame tests identify some cations. They do not measure how much metal is there. That would be quantitative work.
Key points
- metal ions
- nichrome wire
- flame colour
Quick revision
Revision Zone
Review the key facts, formulas and checks before you move on.Flame Tests
Sticky Notes · Quick Revision
Core Idea
- A flame test is a qualitative test for some metal ions.
Key Points
- metal ions
- nichrome wire
- flame colour
Simple Check
- Explain flame tests in your own words and connect it to one chapter example.
How to Answer
- Define the idea, show the main rule or evidence, apply it, and check the final statement.
Common Mistake
- Flame tests identify some cations. They do not measure how much metal is there. That would be quantitative work.
FBISE Exam Tip
- Use the exact term, show working where needed, and include units or labelled evidence.
60-second revision
- metal ions
- nichrome wire
- flame colour
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