Blue hydrated copper(II) sulfate is heated. It turns into white anhydrous copper(II) sulfate and water vapour.
Which change will turn the white solid blue again?
Adding water to the white solid
Adding a catalyst to the white solid
Heating the white solid more strongly
Cooling the white solid in a dry tube
47 exam-style questions on OCR GCSE Chemistry 5.3 Equilibria, covering 5.3.1 Reversible reactions and dynamic equilibrium and 5.3.2 Changing the position of equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.