6 (a) 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 i... show full transcript
Worked Solution & Example Answer:6 (a) Potassium sulfate contains potassium ions, K^+, and sulfate ions, SO_4^{2-} - Edexcel - GCSE Chemistry - Question 6 - 2018 - Paper 1
Step 1
6(a) Give the formula of potassium sulfate.
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Answer
The formula of potassium sulfate is K_2SO_4. This is derived from the combination of two potassium ions (K^+) and one sulfate ion (SO_4^{2-}).
Step 2
6(b) What colour is produced in the flame by the potassium ions?
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Answer
The colour produced in the flame by potassium ions is lilac, corresponding to option B.
Step 3
6(c)(i) Write the word equation for the reaction.
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Answer
The word equation for the reaction when sodium carbonate is mixed with calcium nitrate is:
6(c)(ii) Describe a test to show that solid calcium carbonate contains carbonate ions.
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To test for carbonate ions in solid calcium carbonate, add a few drops of dilute hydrochloric acid to the sample. If carbonate ions are present, effervescence will occur, producing carbon dioxide gas. This gas can be confirmed by bubbling it through limewater, which will turn milky due to the formation of calcium carbonate.
