A sealed monitoring station is powered by a hydrogen fuel cell. Hydrogen and pure oxygen are supplied to the fuel cell through separate pipes.
A valve closes and completely stops the oxygen supply.
Explain at which electrode the oxygen would normally react and what happens to the potential difference produced by the fuel cell when the valve closes.
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.