Chapter 21, Problem 5TE

What happens to the pH of an acidic solution as pure water is added?

To determine

The change in pH of the acidic solution after adding pure water.

Answer to Problem 5TE

The pH of the acidic solution increases after pure water is added.

Explanation of Solution

As pure water is added to the acidic solution, the hydronium ion concentration is lowered as the solution becomes more diluted. This dilution makes the solution less acidic as the number of hydronium ion per unit volume of the solution becomes less. Due to which the $\text{pH}$ value of the solution increases as the pure water is added to the acidic solution. In other words, to make the solution less acidic, pure water is added to increase the $\text{pH}$ value of the acidic solution.

Conclusion:

Therefore, the pH of the acidic solution increases after pure water is added.