A student adds dilute ammonia solution to a solution of iron(II) sulfate. A pale green precipitate forms. When the student filters this precipitate and leaves it on the filter paper, the green solid slowly turns brown where it is exposed to the atmosphere.
Explain this observation.
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.
