An engineer is comparing the reactivity of four metals (chromium, manganese, nickel, and titanium) to assess their suitability for a sacrificial anode system. They measure the temperature rise when each metal is added to a standard solution of copper(II) nitrate.
In the initial trial, the engineer uses a chromium rod, manganese flakes, nickel powder, and a titanium plate.
Describe two improvements that should be made to the metal samples to ensure a fair comparison of the temperature change.
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.