A pH greater than 7 is considered high. This indicates a basic or alkaline solution. The pH scale ranges from 0 to 14, with 7 being neutral. Values below 7 are acidic, while values above 7 are alkaline.
Understanding the pH Scale
The pH scale is a logarithmic scale, meaning each whole number change represents a tenfold change in acidity or alkalinity. For example, a pH of 8 is ten times more alkaline than a pH of 7, and a pH of 9 is ten times more alkaline than a pH of 8.
- Neutral pH (7): Pure water has a pH of 7.
- Acidic pH (less than 7): Solutions with a pH less than 7 are acidic. Examples include lemon juice (around pH 2) and stomach acid (around pH 1.5-3.5).
- Alkaline/Basic pH (greater than 7): Solutions with a pH greater than 7 are alkaline or basic. Examples include baking soda (around pH 9) and household ammonia (around pH 11-12).
The reference material notes that a pH above 7 indicates a base, while a pH above 12.5 is considered hazardous. The human body maintains a narrow pH range of 7.35-7.45. Deviations from this range can have serious health consequences.
Different applications have different thresholds for what constitutes a "high" pH. For example, in some industrial processes, a pH of 9 might be considered high, while in others, a pH of 12 might be more typical. The context is crucial for defining what range is considered "high".
