Adding base causes the pH of a solution to increase.
Step-by-step explanation:
The acidity and alkalinity of a solution is measured with the pH scale. Hydroxide ions and Hydrogen ions are created when the molecules of water gets broken.This reaction is not irreversible. The hydrogen ions concentration to the hydroxide ions concentration is equal in water and also in neutral solutions. The number of hydrogen ions in solutions that are acidic will be more. The number of hydroxide ions in alkaline solutions will be more.
When acids are added to a solution it readily provides hydrogen ions (H+) and reduces the pH of that solution, but when bases are added to a solution it provides hydroxide ions (OH–) and results in the increase of pH. Thus the substances that can easily donate OH– are bases thereby raising the pH of a solution.