Which statement describes the role of the anode and cathode in corrosion?

Which statement describes the role of the anode and cathode in corrosion?

• A. The cathode dissolves faster than the anode
• B. The anode loses metal (oxidizes) to the cathode
• C. There is no metal loss
• D. The anode corrodes because it is reduced

Answer: (B)

In corrosion, oxidation happens at the anodic site: metal atoms lose electrons and enter the electrolyte as ions. Those electrons travel through the external circuit to the cathodic site, where a reduction reaction occurs. So the anode is the location where metal loss (oxidation) happens, driven by the flow of electrons to the cathode. The cathode, by contrast, is where reduction takes place, and it does not undergo metal loss. That’s why the statement that the anode loses metal (oxidizes) to the cathode best describes their roles. The other options would imply no metal loss, or dissolution at the cathode, or reduction at the anode, which aren’t how corrosion processes are set up.

In corrosion, oxidation happens at the anodic site: metal atoms lose electrons and enter the electrolyte as ions. Those electrons travel through the external circuit to the cathodic site, where a reduction reaction occurs. So the anode is the location where metal loss (oxidation) happens, driven by the flow of electrons to the cathode. The cathode, by contrast, is where reduction takes place, and it does not undergo metal loss. That’s why the statement that the anode loses metal (oxidizes) to the cathode best describes their roles. The other options would imply no metal loss, or dissolution at the cathode, or reduction at the anode, which aren’t how corrosion processes are set up.