Figure 3 shows two tests carried out on a white solid and the results of the tests - Edexcel - GCSE Chemistry - Question 2 - 2018 - Paper 1
Question 2
Figure 3 shows two tests carried out on a white solid and the results of the tests.
| test | results |
| --- | --- |
| test 1 | flame test carried out | a yellow fl... show full transcript
Worked Solution & Example Answer:Figure 3 shows two tests carried out on a white solid and the results of the tests - Edexcel - GCSE Chemistry - Question 2 - 2018 - Paper 1
Step 1
Which ion is shown to be present by the result of test 1?
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Answer
The yellow flame observed in the flame test indicates the presence of sodium ions. Sodium typically produces a bright yellow flame, distinguishing it from other metal ions.
Step 2
State the name of the gas given off in test 2.
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Answer
The gas given off in test 2 is hydrogen. This is evidenced by effervescence when dilute hydrochloric acid is added to the white solid.
Step 3
State the name of the ion shown to be present in the white solid by the result of test 2.
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Answer
The ion shown to be present in the white solid is calcium. This is inferred from the result of the limewater test, where the effervescence indicates the release of carbon dioxide, which turns limewater milky, confirming the presence of calcium ions.
