Demonstration of the voltage generated by an iodine-permanganate galvanic cell. The beakers contain a solution of potassium iodide (left) and potassium permanganate solution (right), linked by a salt-saturated bridge of wet paper. A voltmeter is connected to two graphite electrodes. When the electrode is placed in the permanganate, a voltage of 0.83V is seen on the voltmeter. This is produced as permanganate is a powerful oxidising agent and it oxidises iodide ions to iodine. The permanganate itself is reduced to manganate ions. This generates a flow of electrons and ions around the circuit.