What Are Half Equations

In this video, we will learn how to write half equations for simple redox reactions. A half-equation shows what happens at one of the electrodes during electrolysis, so we need to be able to complete and balance half-equations for these reactions. Remember that oxidation occurs at the anode, and reduction occurs at the cathode. Oxidation means the loss of electrons and reduction means the gain of electrons. Electron transfer has to happen, with one substance losing electrons and another substance gaining electrons. Half equations take out half of the reaction - so looking just at the loss or gain of electrons. We use a copper and silver example in this video to show the half equations. Each equation represents HALF of a REDOX reaction - either the reduction reaction or the oxidation reaction. When the two equations are added together to form the final redox reaction, you can see everything: the number of electrons and are balanced.