Page 2 - 3. LESSON NOTES(CH-2-PH IN EVERYDAY LIFE)

2- pH of the soil should be equal to 7 [neutral] for healthy growth of
plants.

• If pH value of soil is found lower than 7, i.e. soil becomes acidic.
It is treated with calcium oxide, calcium hydroxide or chalk (Basic in nature).
After treatment excess acid present in soil neutralizes and soil becomes fertile
again.
• Similarly, often pH value of soil becomes greater than 7, i.e. becomes
basic. In such condition also soil is treated with neutral manure or compost or
pyrite or gypsum which neutralizes the basic nature of soil.

3- Acid in our stomach has low pH and antacids are alkaline and have
high pH that neutralizes the acid.

• Walls of our stomach produce hydrochloric acid which kills germs

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