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Some metal ions can be detected using a flame test - Edexcel - GCSE Chemistry - Question 2 - 2017 - Paper 1
Question 2
Some metal ions can be detected using a flame test. A flame test involves the following steps. These steps are not in the correct order. 1 hold the flame test wire i... show full transcript
Worked Solution & Example Answer:Some metal ions can be detected using a flame test - Edexcel - GCSE Chemistry - Question 2 - 2017 - Paper 1
Step 1
What is the correct order of steps for a flame test?
Answer
The correct order of steps for a flame test is:
- Clean the flame test wire to avoid contamination.
- Dip the flame test wire into the substance being tested.
- Hold the flame test wire in the Bunsen flame to observe the color change.
Thus, the correct option is A (1 – 3 – 2).
Step 2
Draw one straight line from each test to the ion it shows to be present.
Answer
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The test with dilute hydrochloric acid followed by barium chloride shows the presence of:
- Carbonate ion, CO₃²⁻ (due to the formation of a white precipitate).
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The test with dilute nitric acid followed by silver nitrate shows the presence of:
- Sulfate ion, SO₄²⁻ (also resulting in a white precipitate).