Photo AI
10 (a) A sample of potassium carbonate is contaminated with a small amount of sodium carbonate - Edexcel - GCSE Chemistry - Question 10 - 2019 - Paper 1
Question 10
10 (a) A sample of potassium carbonate is contaminated with a small amount of sodium carbonate. When a flame test is carried out on the sample, a bright yellow flame... show full transcript
Worked Solution & Example Answer:10 (a) A sample of potassium carbonate is contaminated with a small amount of sodium carbonate - Edexcel - GCSE Chemistry - Question 10 - 2019 - Paper 1
Step 1
Describe how you could show that potassium and sodium ions are present in this sample.
Answer
To demonstrate the presence of potassium and sodium ions in the sample, a flame test can be employed. When the sample is heated in a Bunsen burner flame, sodium ions typically produce a bright yellow flame. To confirm the presence of potassium ions, a sample can be introduced in a separate flame test; potassium ions produce a lilac or light purple flame.
By comparing the emitted colors from both tests, we can establish that both potassium and sodium ions are present in the sample.
Step 2
Write the ionic equation for this reaction.
Answer
The ionic equation for the reaction between hydrochloric acid and sodium carbonate can be derived from the balanced reaction:
ightarrow H_2O(l) + CO_2(g)$$ This equation represents the ions that participate in the reaction, omitting the spectator ions (sodium and chloride) from the total ionic equation.