Rainwater with a pH below 5.6 is termed as acid rain, which can have detrimental effects on ecosystems, including harming aquatic life and damaging vegetation and infrastructure.

The human body operates within the pH range of 7.0 to 7.8, maintaining a slightly alkaline environment crucial for various physiological processes and overall health.

The strength of acids and bases depends on the number of H+ ions and OH– ions they produce, respectively. Strong acids produce more H+ ions, while weak acids produce fewer H+ ions.

Paper impregnated with universal indicator is commonly used for measuring pH. The indicator changes color depending on the acidity or alkalinity of the solution, allowing for pH determination.

As the pH value increases from 7 to 14, it represents an increase in the concentration of OH– ions in the solution, indicating an increase in the strength of the alkali.