Pure water has a theoretical pH of 7, but in reality, it can vary slightly? A simple explanation of the chemistry of water!
■Why is the pH of pure water theoretically "7"?
Pure water does not contain substances that can be classified as either acidic or alkaline. Water naturally ionizes very slightly, resulting in hydrogen ions that indicate acidity and hydroxide ions that indicate alkalinity being present in equal concentrations, which makes it neutral, or pH 7.
■Why does actual water deviate from pH 7?
When substances that indicate acidity or alkalinity dissolve in water, that water will show acidic or alkaline properties. It is known that even pure water, which should theoretically have a pH of 7, becomes slightly acidic when it absorbs carbon dioxide from the air, resulting in a pH of about 5.6.
■How should pure water be handled to remain stable?
As mentioned, pure water has a tendency to be influenced by its surrounding environment. When accurate pH values are needed for analysis or experiments, it is important to handle it carefully, such as minimizing exposure to air.