A theatre uses rechargeable cells in wireless microphones. During a performance, chemical reactions in each cell supply electrical energy. When a cell stops supplying electricity, it is connected to an external electrical current. The cell can then power a microphone again.
Why can the cell power the microphone again?
The external current keeps the reactions in the electricity-producing direction until the reactants return.
The external current reverses the chemical reactions and restores the reactants.
The external current is stored in the cell and released later as an electric current.
The external current transfers replacement reactants from the charger into the cell.
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.