A student carried out a flame test on a sample of solid copper(II) sulfate.
They followed this method:
Step 1: Dip a damp wooden splint into the solid copper(II) sulfate sample.
Step 2: Hold the wooden splint in a hot, roaring Bunsen burner flame.
Step 3: Observe the flame colour produced.
The student observed a bright yellow-orange flame and concluded that the copper(II) sulfate was heavily contaminated with sodium ions.
This is not a valid conclusion because of the experimental method used.
Explain one improvement that the student could make to their method to obtain a valid result.
Practise Edexcel GCSE Chemistry Qualitative analysis: tests for ions with exam-style questions for Foundation and Higher tier. 127 questions, matched to the Edexcel GCSE Chemistry (1CH0) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
