Write a balanced half-reaction describing the oxidation of aqueous chloride anions to gaseous dichlorine.

Oxidation is a process which involves losing electrons in a reaction by an ion, atom or a molecule. It happens when the oxidation state of the ion, atom or the molecule is being increased. Chloride anions has an oxidation state of - 1 and dichlorine has an oxidation state of zero or neutral charge. The balanced half-reaction would be written as:

2Cl - = Cl2 + 2e-

To balance the charge on both sides, two electrons should be produced or released by the anion form of chlorine. Being oxidized would mean that the charge of the ion or molecule is being increased. In this case, it is increased from - 1 to 0.