What would you predict if you had first mixed the catalase (100%) in serial solutions of varying pHs of 3, 5, 7, 9, and 11

Catalase has no effect on the pH of solutions.

Explanation:

Catalase has no effect on the pH of solutions when added to these solutions because it has a neutral pH of 7. So when Catalase is added to solutions having pH 3, the pH will remain 3, when Catalase is added to solutions having pH 5, the pH will remain 5, when Catalase is added to solutions having pH 7, the pH will remain 7, when Catalase is added to solutions having pH 9, the pH will remain 9 and when Catalase is added to solutions having pH 11, the pH will remain 11.