A student tests for the presence of transition metal ions by adding dilute sodium hydroxide solution to a solution containing the sample metal ions.
Which of these observations is evidence that a precipitate has formed?
A gas is produced and effervescence is seen
The solution becomes cloudy as an insoluble solid forms
The mixture rapidly changes temperature
A flame burns with a characteristic color
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.
