What is pH scale?
The pH scale is a measure of the acidity or alkalinity of a substance. It ranges from 0 to 14, with 7 being neutral. Substances with a pH below 7 are considered acidic, while those with a pH above 7 are alkaline. The pH scale is logarithmic, meaning that each whole number change represents a tenfold difference in acidity or alkalinity.

Key points about the pH scale:
- pH stands for "potential of hydrogen" and measures the concentration of hydrogen ions in a solution.
- A lower pH indicates a higher concentration of hydrogen ions, making the solution more acidic.
- An increase in pH value by one unit represents a tenfold decrease in hydrogen ion concentration.
- The pH scale is important in various fields such as chemistry, biology, and environmental science.

Acidic, neutral, and alkaline substances:
- Acidic substances have a pH below 7. Examples include lemon juice and vinegar.
- Neutral substances have a pH of 7. Pure water is an example of a neutral substance.
- Alkaline substances have a pH above 7. Examples include baking soda and ammonia.

Importance of pH scale:
The pH scale is crucial in various applications, such as:
- Determining the acidity of soil for agriculture.
- Monitoring the pH of swimming pools and aquariums for the health of aquatic life.
- Understanding the pH of the human body for proper functioning.
In conclusion, the pH scale is a fundamental concept in chemistry that helps us understand the acidity or alkalinity of substances. It plays a significant role in various aspects of our daily lives and scientific research.

A measure of acidity or alkalinity of water soluble substances....