Negative logarithm of hydrogen ion is called pH .-log(h+).
it helps in acidity value of the hcl in stomach.,citric acid

PH stands for Potential of Hydrogen. pH value is that scale which determines whether the solution is acidic or basic.

Solution less than 7 is Acidic and greater than 7 is basic in nature.

It's importance in our daily life are = 
1. Our body works with 7 to 7.8 of pH.
2. Less than 5.5 pH value of our mouth causes Tooth Decay.
3.Blood has pH value between 7.35 to 7.45
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