Potassium sulfate contains potassium ions, K^+, and sulfate ions, SO_4^{2-}.
Use this information to give the formula of potassium sulfate.
(b) A flame test is car... show full transcript
Worked Solution & Example Answer:Potassium sulfate contains potassium ions, K^+, and sulfate ions, SO_4^{2-} - Edexcel - GCSE Chemistry - Question 6 - 2018 - Paper 1
Step 1
a) Use this information to give the formula of potassium sulfate.
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Answer
The formula for potassium sulfate is K_2SO_4. This is derived from the fact that there are two potassium ions (K^+) for every sulfate ion (SO_4^{2-}) in the compound.
Step 2
b) What colour is produced in the flame by the potassium ions?
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Answer
The potassium ions produce a lilac colour in the flame test. Therefore, the answer is B.
Step 3
c(i) Write the word equation for the reaction.
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c(ii) Describe a test to show that solid calcium carbonate contains carbonate ions.
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Answer
To test for carbonate ions in solid calcium carbonate, you can:
Add a few drops of dilute hydrochloric acid (HCl) to the solid calcium carbonate in a test tube.
Observe for the formation of bubbles, which indicates the release of carbon dioxide gas (CO_2).
You can further confirm that CO_2 is produced by passing the gas through limewater, which will turn milky if carbon dioxide is present, indicating the presence of carbonate ions.
