A small amount of ammonium chloride is placed at the centre of a long glass tube. The centre of the tube is heated while both ends remain cool. After a short time, there is less solid at the centre and a white deposit has formed in the cooler regions.
Explain why the white deposit forms in the cooler regions and suggest what happens to the deposit if one of these regions is warmed.
124 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.