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Understanding pH and Acid-Base Chemistry
Formula
pH is a logarithmic scale used to specify the acidity or basicity of an aqueous solution. Values below 7 indicate acidic solutions, 7 is neutral, and values above 7 indicate basic (alkaline) solutions. The pH scale is fundamental in chemistry, biology, medicine, and environmental science.
The pH value is calculated as the negative base-10 logarithm of the hydrogen ion activity: pH = -log10([H+]). Because the scale is logarithmic, each whole pH unit represents a tenfold change in hydrogen ion concentration. For example, a solution with pH 3 is ten times more acidic than one with pH 4.
Common use cases:
- Water quality testing
- Laboratory solution preparation
- Soil acidity analysis
Frequently Asked Questions
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