You probably need to try out this experiment at school. Using a small battery-operated voltmeter, perform the SmallScale experiment determining cell potentials.

Potentiometry during silver one pot reactions shows the importance of concentration in determining cell potential. This is an expensive experiment for advanced students.

Using specialized electrodes and measuring cell potentials when these electrodes are immersed into test solutions is a very common way to determine concentrations. The pH electrode is one of the most common "specific ion electrodes." Demonstrate this to your students using the electronic resource on the fluoride ion specific electrode.