Question

Carrie is conducting an experiment on a solution. The solution’s initial pH is 10. Then, as Carrie gradually adds Compound X into the solution, the pH decreases to 5. Which is the most likely identity of Compound X? *

Answer 1

Compound X must be an acid

Step-by-step explanation:

Acids have a lower pH than alkaline solutions. When you add an acid to a solution, the pH drops, as has happened here. If the pH did not change, we would assume compound X was neutral. If the pH increased, we would assume compound X was even more alkaline than pH 10.