Normal water, specifically drinking water, typically has a pH range between 6.5 and 8.5.
Understanding pH in Water
pH is a measure of how acidic or basic (alkaline) a substance is. It's measured on a scale from 0 to 14, where:
- 7 is neutral (like pure water)
- Below 7 is acidic
- Above 7 is basic or alkaline
While pure water has a pH of 7, natural water rarely does. This is because various factors influence the pH of water.
Factors Affecting Water pH
The reference information states that factors such as acid rain and the presence of limestone can influence the pH of natural water. Here are some additional examples:
- Acid Rain: Acid rain can lower the pH of water, making it more acidic.
- Geological Formations: Water flowing through limestone formations can become more alkaline, raising the pH.
- Dissolved Minerals: Various dissolved minerals and chemicals in the water can affect its pH.
Measurement of pH
The pH of an aqueous sample is usually measured using an electrometric method with a glass electrode, according to the reference. This is a precise method used in laboratories and water treatment facilities.
Implications of pH Levels
While the 6.5-8.5 range is generally safe for drinking water, extreme pH values can have negative consequences:
- Low pH (Acidic): Water with low pH can be corrosive, potentially leaching metals from pipes and plumbing fixtures.
- High pH (Alkaline): While less common than low pH issues, very alkaline water can have an unpleasant taste and might also pose health concerns in extreme cases.
Table of pH Values
| Water Type | Typical pH Range |
|---|---|
| Normal Drinking Water | 6.5 - 8.5 |
| Pure Water | 7 |
| Acidic Water | Below 6.5 |
| Alkaline Water | Above 8.5 |
Conclusion
The normal pH for drinking water is between 6.5 and 8.5. Factors like the environment and geology can affect the pH of water, but it is generally safe within this range.
