A remote water-quality sampler requires a battery with a voltage of at least 7.0 V. Identical cells, each with a voltage of 1.2 V, are connected in series with the cells facing the same way.
Calculate the minimum number of cells needed and the voltage of the battery made from these cells.
90 exam-style questions on AQA GCSE Chemistry 5.2 Chemical cells and fuel cells, covering 5.2.1 Cells and batteries, 5.2.2a Fuel cells, and 5.2.2b Half equations for hydrogen fuel cells. Each one has a worked solution and a mark scheme showing where the marks go.