This question is about chemical cells.
A student investigated the voltage produced by different chemical cells using the apparatus shown below.
The student used the following method:
- Use aluminum as electrode Y.
- Record the cell voltage.
- Repeat steps 1 and 2 using different metals as electrode Y.
a.[2]
Suggest two variables that must be controlled in this investigation to ensure valid results.
b.
[3]
Table 1 shows the student's results:
| Electrode Y | Voltage of cell in volts (V) |
|---|---|
| Silver | -0.94 |
| Gold | -1.64 |
| Aluminum | +1.52 |
| Tin | 0.00 |
| Iron | +0.30 |
| Zinc | +0.62 |
Write the six metals used for electrode Y in order of reactivity from most reactive to least reactive. Justify your order using the data.
c.[1]
Which of the following pairs of metals would produce the greatest voltage when used as the electrodes in a similar cell? Use the data in Table 1.
- Zinc and Silver
- Aluminum and Silver
- Aluminum and Gold
- Iron and Gold