PH

The pH scale indicates the degree of acidity or alkalinity of a solution.  Definition of pH is the logarithm of the reciprocal of the hydrogen-ion \((H^+)\) concentration.  Scale range is usually 0 to 14 where the midpoint is 7.0.  When the pH is 7.0, the fluid is said to be neutral.  Higher values denote alkalinity; lower values denote acidity.  When pH is 0, the solution is the most acidic.  When the pH is 14, the solution is most basic.