Question 8
FA technician tests a white solid S using the apparatus shown. A gas is produced when dilute acid contacts S. The gas is passed into solution L.
a.[4]
Name a suitable dilute acid and identify solution L for a carbonate test. State the positive observation in L and the ion in S indicated by that observation.
b.[2]
Explain why the delivery tube must end below the surface of L. State the effect of a leak in the stopper on the reliability of a negative result.
c.[3]
A fresh sample of S gives a yellow flame. Use both results to suggest the name and formula of S, assuming it is a pure salt. Explain why the flame test alone would not identify the complete compound.
10.1 Qualitative analysis: tests for ions Questions
35 exam-style questions on Edexcel GCSE Chemistry 10.1 Qualitative analysis: tests for ions, covering 10.1.1 Principles of ion tests and flame tests, 10.1.2 Tests for cations and for ammonia, 10.1.3 Tests for anions, 10.1.4 Identification of ions in unknown salts, and 10.1.5 Instrumental methods of analysis. Each one has a worked solution and a mark scheme showing where the marks go.