The pH Scale
The Strength Meter
The Power of Hydrogen
The pH scale (0-14) measures how strong an acid or base is.
Key Points
- pH < 7: Acidic; pH = 7: Neutral; pH > 7: Basic.
- Potenz: The 'p' in pH stands for power (potenz in German).
- Testing: Measured using indicators like pH paper strips.
Olympiad Fact
A shift of 1 point on the pH scale equals a 10-fold difference in strength.
Universal Indicator & Testing
Precise Strength Measurement
Universal indicator is a mixture of several indicators that provides a wide range of colors across the pH scale.
Key Points
- Provides exact pH values through specific color changes.
- Red/Orange colors indicate strong/weak acids.
- Blue/Violet colors indicate strong/weak bases.
- The final color is matched against a standard chart.
Olympiad Fact
Universal indicator is much more precise than simple litmus as it shows the relative strength, not just nature.
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