A student carried out some tests on copper sulfate - Edexcel - GCSE Chemistry - Question 4 - 2021 - Paper 1
Question 4
A student carried out some tests on copper sulfate.
(a) A flame test was carried out on some copper sulfate crystals.
The student used the following method.
step ... show full transcript
Worked Solution & Example Answer:A student carried out some tests on copper sulfate - Edexcel - GCSE Chemistry - Question 4 - 2021 - Paper 1
Step 1
State why in step 1 the wire is dipped in hydrochloric acid and held in a roaring Bunsen burner flame.
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Answer
The wire is dipped in hydrochloric acid to clean it and prevent contamination of the sample.
Step 2
State why in step 2 the wire is dipped in hydrochloric acid again before dipping it in the copper sulfate crystals.
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Answer
The wire is dipped in hydrochloric acid again so that the solid vapourises more easily and so that the solid sticks onto the wire.
Step 3
What colour should be seen when the flame test is carried out on copper sulfate?
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Answer
The colour seen when the flame test is carried out on copper sulfate should be blue-green.
Step 4
Give an advantage of using a flame photometer, rather than a flame test, to test for copper ions.
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Answer
A flame photometer provides a quantitative measurement of the concentration of copper ions, which is more accurate than a visual flame test.
