An electrochemical researcher is testing different combinations of metal electrodes in a simple chemical cell containing a dilute sulfuric acid electrolyte.
The list below shows the metals available to the researcher, arranged in order of their chemical reactivity:
Which two metal electrodes from this list should the researcher select to construct a cell that produces the highest voltage?
State the reason for your choice of metals in part (a).
The researcher first measures the voltage of a cell using iron and silver electrodes. If they then substitute the iron electrode with an aluminium electrode, describe and explain the change in the measured voltage.