An offshore monitoring buoy is tested with each power source connected to the same constant electrical load. Each power source starts the test ready for use. The test ends after 18 hours.
| Power source | Observation during the test |
|---|---|
| Hydrogen fuel cell | Still supplying electricity when the test ended after 18 hours |
| Rechargeable battery | Stopped supplying electricity after 7 hours |
Explain the difference between the results for the two power sources. Predict what would happen in a second test if the hydrogen supply to the fuel cell stopped after 10 hours.
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.