Cathodic Protection Tester Practice Exam

What occurs at the anode in an electrochemical corrosion cell?

1. Negatively charged ions enter the anode

2. Positively charged ions leave the anode and enter the electrolyte

3. Electrons are generated at the anode

4. Current flows from electrolyte to anode

The correct answer is: Positively charged ions leave the anode and enter the electrolyte

At the anode of an electrochemical corrosion cell, the key process that occurs is the oxidation half-reaction, where metal atoms lose electrons and form positively charged metal ions. This loss of electrons causes positively charged ions to leave the anode and enter the surrounding electrolyte. When metal undergoes corrosion, it typically dissolves into the electrolyte as its atoms are stripped of electrons, allowing them to transition into ionic form. Therefore, the positively charged ions generated at the anode are the result of the oxidation process. This movement is essential in electrochemical reactions, as it contributes to the overall flow of current in the system where electrons are generated at the anode but flow towards the cathode, creating a complete circuit. Understanding this process is crucial in cathodic protection systems, as mitigating corrosion involves managing these anodic reactions effectively. The other choices do not accurately represent the electrochemical behaviors at the anode, which are focused on the loss of electrons and the formation of cations.