Why is extracting a metal by electrolysis more expensive than heating its oxide with carbon?
The metal formed is less reactive than carbon
The ore must first be dissolved in water
Large amounts of electrical energy are needed
More carbon is needed to reduce the ore
45 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.