Final answer:
AC copper-coated electrodes are used in welding and are coated with copper to improve conductivity and resist oxidation. In electroplating, these electrodes facilitate the electrochemical process where copper ions are transferred from an anode to a metal cathode, thereby plating the cathode with copper.
Step-by-step explanation:
An AC copper-coated electrode is typically used in welding and refers to an electrode that has been coated with a layer of copper to enhance its electrical conductivity and prevent oxidation of the electrode during use. In electroplating, such as when plating a metal with copper, the process involves an electrochemical cell where copper ions from a copper sulfate solution are reduced onto a metal cathode, resulting in a copper-coated surface. This is denoted by the half-reactions: at the anode (Cu (s) → Cu²+ (aq) + 2e⁻), copper metal is oxidized, and at the cathode (Cu²+ (aq) + 2e⁻ → Cu° (s)), copper ions are reduced to copper metal. This illustrates the fundamental process of electroplating, which is widely applied in various industrial applications to coat objects with metals like chromium, gold, silver, and platinum for enhanced properties.