The flow chart shows the steps used to identify a sample of a substance - HSC - SSCE Chemistry - Question 13 - 2016 - Paper 1
Question 13
The flow chart shows the steps used to identify a sample of a substance.
Flame test on a sample
Dissolve a fresh sample in water
Add 0.1 mol L⁻¹ hydrochloric acid... show full transcript
Worked Solution & Example Answer:The flow chart shows the steps used to identify a sample of a substance - HSC - SSCE Chemistry - Question 13 - 2016 - Paper 1
Step 1
Test 1: Flame test on a sample
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Answer
A bright orange flame indicates the presence of sodium ions in the sample. This is consistent with sodium sulfate, which is known to produce a bright orange flame when burned.
Step 2
Test 2: Add 0.1 mol L⁻¹ hydrochloric acid to sample
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Answer
No bubbles should be formed because sodium sulfate does not produce carbon dioxide gas when reacting with hydrochloric acid.
Step 3
Test 3: Add Ba²⁺ ions to sample
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Answer
A white precipitate should be formed, indicating the presence of sulfate ions, which react with barium ions to form barium sulfate.
