When parietal cells secrete protons into the stomach, what would you predict would happen to the pH of the blood? Would this process be affected if you treated with an inhibitor of the enzyme carbonic anhydrase?

I can answer the first part of this:

An acid is defined as any material with a higher concentration of hydrogen ions [H+] than hydroxide [OH-]. By adding protons to the blood, you are making it more acidic (lower pH).