When cathodic protection is applied, what change occurs at the cathode?

When cathodic protection is applied, the electrochemical processes that occur at the cathode lead to a change in the local environment, particularly regarding pH levels. At the cathode, a reduction reaction takes place, most commonly the reduction of hydrogen ions to hydrogen gas or the reduction of metal cations to their elemental forms.

This reduction reaction consumes hydrogen ions (H+) from the solution, resulting in a decrease in their concentration. According to Le Chatelier's Principle, when the concentration of hydrogen ions decreases, the pH of the solution increases, making the environment more basic. Therefore, the area around the cathode becomes more basic as hydroxide ions (OH-) are produced in greater amounts to balance the reaction, and this increased presence of hydroxide ions raises the pH.

In summary, when cathodic protection is effectively applied, it indeed causes the local environment at the cathode to become more basic due to the consumption of hydrogen ions during the cathodic reactions. This is why the correct answer is that the environment at the cathode becomes more basic.