Question

importance of ph value in our everyday life as well as in plants with some examples

Answer 1

 PH IN PLANTS      Plants require a specific pH of the soil for their proper growth. Plants cannot grow in too alkaline or too acidic soils. Therefore, for proper cultivation of crops it is important to have knowledge of the pH of the soil. If the soil is too acidic then its pH can be raised by adding lime (or slaked lime) which neutralizes the excess acid in the soil.
USES IN DAILY LIFE OF PH
 HELPS IN DIGESTION
REGULATES BREATHING 
ACTIVATE ENZHYMES

Answer 2

In our mouth too, if the pH will increase 5.5 then it will promote the tooth-enamel decay.
If the pH of the rain ☔ increases beyond 5.6 then it is further considered as acid rain