Compound Z\textbf{Z}Z is a bright blue, crystalline solid. It contains copper(II) ions (Cu2+\text{Cu}^{2+}Cu2+), sulfate ions (SO42−\text{SO}_4^{2-}SO42−) and water of crystallisation.
A student dissolved some of compound Z\textbf{Z}Z in water and then added aqueous sodium hydroxide solution. She obtained a blue precipitate.
Give the formula of the blue precipitate formed in the reaction.
Another student tested a solution of compound Z\textbf{Z}Z for sulfate ions using dilute hydrochloric acid, followed by a few drops of barium chloride solution. She obtained a white candidate precipitate.
Why is the dilute hydrochloric acid necessary in this test?
The empirical formula of compound Z\textbf{Z}Z is CuSO9H10\text{CuSO}_{9}\text{H}_{10}CuSO9H10.
Write the formula of compound Z\textbf{Z}Z to show its water of crystallisation.
Outline how you would carry out a flame test on a solid sample.
35 exam-style questions on Edexcel IGCSE Chemistry Chemical tests. Each one has a worked solution and a mark scheme showing where the marks go.