Figure 7. Hydrogen and oxygen gas collected at the electrodes react with each other when the fuel cell is in action

From

Teaching Sustainability in the Chemistry Classroom: Exploring Fuel Cells in Simple Hands-on Experiments with Hydrogen, Sugar and Alcohol

Rebecca Grandrath, Claudia Bohrmann-Linde

World Journal of Chemical Education. 2019, 7(2), 172-178 doi:10.12691/wjce-7-2-17