Questions: Which change would decrease the pH of a base in a solution at equilibrium? (1 point) decreasing the concentration of OH^- ions increasing the initial concentration of solute decreasing the amount of water added to the solute increasing the strength of the base

Solution Steps

The pH of a solution is a measure of its acidity or basicity. For basic solutions, the pH is greater than 7, and it is related to the concentration of hydroxide ions (\(\mathrm{OH}^-\)). A decrease in the concentration of \(\mathrm{OH}^-\) ions will result in a decrease in pH, making the solution less basic (or more acidic).

1. Decreasing the concentration of \(\mathrm{OH}^-\) ions: This would directly decrease the pH of the solution, as fewer \(\mathrm{OH}^-\) ions mean the solution is less basic.

2. Increasing the initial concentration of solute: This typically increases the concentration of \(\mathrm{OH}^-\) ions if the solute is a base, thus increasing the pH.

3. Decreasing the amount of water added to the solute: This would increase the concentration of \(\mathrm{OH}^-\) ions, as the solution becomes more concentrated, thus increasing the pH.

4. Increasing the strength of the base: A stronger base would dissociate more \(\mathrm{OH}^-\) ions, increasing the pH.

The change that would decrease the pH of a base in a solution is the one that reduces the concentration of \(\mathrm{OH}^-\) ions. Therefore, the correct option is:

• Decreasing the concentration of \(\mathrm{OH}^-\) ions.

Final Answer