pH stands for power of hydrogen, which is a measurement of the hydrogen ion concentration in the body. In chemistry, pH is a logarithmic scale used to specify the acidity or basicity of an aqueous solution. pH value is measured in units of moles per liter, of hydrogen ions. The article presents the list of pH Values of Common Substances. This article plays a prominent role in GA/GK preparation in many competitive exams.

pH value is a measure of acidity or alkalinity of water soluble substances (pH stands for 'potential of Hydrogen'). A pH value is a number from 1 to 14, with 7 as the middle (neutral) point. Values below 7 indicate acidity which increases as the number decreases, 1 being the most acidic. Values above 7 indicate alkalinity which increases as the number increases, 14 being the most alkaline. pH scale, is not a linear scale like a centimeter or inch scale (in which two adjacent values have the same difference). It is a logarithmic scale in which two adjacent values increase or decrease by a factor of 10.
Ex: A pH of 3 is ten times more acidic than a pH of 4, and 100 times more acidic than a pH of 5. Similarly, a pH of 9 is 10 times more alkaline than a pH of 8, and 100 times more alkaline than a pH of 7. Invented in 1909 by the Danish biochemist S. P. Sorensen (1869-1939).
Below table contains the list of pH Values of Common Substances.