In an investigation into rusting, anhydrous calcium chloride is sealed into one of the test tubes. Why is it used?
It reacts with the oxygen in the air inside the sealed test tube
It reacts with the iron and forms a barrier on the nail surface
It removes water vapour from the air inside the sealed test tube
It speeds up the reaction between the iron and the oxygen present
40 exam-style questions on AQA GCSE Chemistry 10.3 Using materials, covering 10.3.1 Corrosion and its prevention, 10.3.2 Alloys as useful materials, and 10.3.3 Ceramics, polymers and composites. Each one has a worked solution and a mark scheme showing where the marks go.