The pH Phosphoric acid is a non-constant value. Like other acids and alkaline compounds whose pH values are measured on a standard pH scale, the value of a given solution of the acid depends on its concentration.
According to Aqioin.com, pH values range from one to 14. Values below seven represent different acidic levels of acidic solutions. On the other hand, values above seven represent the alkaline levels of alkaline substances.
In respect of phosphoric acid, its acidity on a pH scale depends largely on its concentration. A highly concentrated acid solution has a lower pH value than a lowly concentrated acid solution. Strong acids have low pH values, whereas weak acids have high pH values.