Which change would decrease the pH of a base in a solution at equilibrium?(1 point)
Responses
decreasing the amount of water added to the solute
decreasing the amount of water added to the solute
decreasing the concentration of OH– ions
decreasing the concentration of OH – ions
increasing the initial concentration of solute
increasing the initial concentration of solute
increasing the strength of the base
increasing the strength of the base
Decreasing the concentration of OH– ions would decrease the pH of a base in a solution at equilibrium.
Are you sure?
Decreasing the concentration of OH– ions would decrease the pH of a base in a solution at equilibrium.
To determine which change would decrease the pH of a base in a solution at equilibrium, we need to understand the factors that affect pH and how they are related to bases.
pH measures the acidity or alkalinity of a solution and is determined by the concentration of hydrogen ions (H+) present in the solution. In a basic solution, the concentration of hydroxide ions (OH-) is higher than the concentration of hydrogen ions, resulting in a higher pH value.
Now, let's consider the given responses:
1. Decreasing the amount of water added to the solute:
This change would not directly affect the pH of a base. The concentration of hydroxide ions and the concentration of hydrogen ions would remain the same since they are determined by the strength of the base and the equilibrium between the base and its conjugate acid.
2. Decreasing the concentration of OH- ions:
This change would actually increase the pH of the solution. As stated earlier, a higher concentration of hydroxide ions leads to a higher pH, so reducing the concentration of OH- ions would decrease the alkalinity and thus increase the acidity. Therefore, this option is incorrect.
3. Increasing the initial concentration of solute:
In this case, increasing the concentration of the base would lead to an increase in the concentration of hydroxide ions (OH-), and as a result, the pH of the solution would increase (making it more basic). So, this option would not decrease the pH of the base.
4. Increasing the strength of the base:
Strengthening the base means it will more readily release hydroxide ions (OH-). As a result, the concentration of hydroxide ions will increase, leading to a higher pH. Therefore, increasing the strength of the base would not decrease the pH.
Based on the explanations above, the correct answer is:
Decreasing the concentration of OH – ions
By reducing the concentration of hydroxide ions in the solution, the alkalinity decreases, and the pH of the base will decrease, making it more acidic.