An engineer investigates the relative reactivity of four different metals by adding each metal to a sample of aqueous copper(II) sulfate (CuSO4\text{CuSO}_4CuSO4) solution and measuring the maximum temperature increase.
State two variables, apart from the mass of the metals, that the engineer must control to ensure a fair test.
110 exam-style questions on Edexcel GCSE Chemistry 5.1 Obtaining and using metals, covering 5.1.1 The reactivity series of metals, 5.1.2 Displacement reactions as redox reactions, 5.1.3 Extracting metals from ores by reduction, 5.1.4 Biological methods of metal extraction, 5.1.5 Resistance to oxidation and recycling metals, and 5.1.6 Life cycle assessment. Each one has a worked solution and a mark scheme showing where the marks go.