A recycling centre compares three recovered metal samples, P, Q and R. Zinc is more reactive than each of the three metals.
For each test, the two metals shown were used as electrodes in an electrolyte. The electrolyte and all other conditions were kept the same. Magnesium is more reactive than zinc.
| Metals used as electrodes | Voltage in V |
|---|---|
| zinc and P | 0.81 |
| zinc and Q | 0.34 |
| zinc and R | 0.56 |
| magnesium and zinc | 0.67 |
Give the letter of the most reactive of the three recovered metals.
Explain your answer to part a.
A cell is made using magnesium and metal Q as the two electrodes, under the same conditions.
Predict the voltage of this 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.