BioMedical Admissions Test (BMAT) Practice Test

During electrolysis, the anode is the site where oxidation occurs, which is defined as the process of losing electrons. When an ion or atom undergoes oxidation at the anode, it releases electrons into the electrical circuit. This means that as the current flows through the electrolytic cell, species at the anode give up their electrons. For instance, in the electrolysis of water, hydroxide ions (OH⁻) are oxidized at the anode, leading to the release of oxygen gas and the production of water. This process illustrates how the loss of electrons at the anode directly correlates with the oxidation of the reacting species. The other options do not correctly describe the process at the anode. Gaining electrons (option A) would occur at the cathode, where reduction takes place. The formation of new compounds (option C) may happen overall, but that is not a specific characteristic of the electrochemical reactions at the anode. Unreacted ions dissolving (option D) refers more to the remaining ions in the solution that have not participated in the reaction at the electrodes, rather than the specific reaction occurring at the anode.