pH Scale:
The pH scale measures the acidity or basicity of a solution. It ranges from 0 to 14:
pH < 7: Acidic solution (e.g., lemon juice, vinegar).
pH = 7: Neutral solution (e.g., pure water).
pH > 7: Basic solution (e.g., soap solution, bleach).
Importance of pH:
1. Human Health: The human body maintains a pH of around 7.4 in the blood. Any deviation can cause health problems.
2. Soil pH: The growth of crops depends on the pH of the soil. Most plants grow best in soil with a pH of 6 to 7.
3. Water Quality: The pH of drinking water should be neutral or slightly alkaline for safety.
4. Industrial Processes: The pH of solutions is carefully monitored during chemical reactions in industries.
Calculation of pH:
The pH is calculated using the formula:
pH=−log[H3O+]
Example Calculation:
1. Use the pH equation which is: pH=−log[H3O+]
0.055 M HBr, HBr is a strong acid
[H3O+] = 5.5 X 10-2 M
pH = -log(5.5 X 10-2) = 1.26
Thus, the solution is strongly acidic.