See Also:

pH (iou)



pH noun. E20.
[from p repr. German Potenz power + H, symbol for the hydrogen ion.]
Chemistry. Acidity or alkalinity of a solution, soil, etc., expressed numerically as the logarithm to the base 10 of the reciprocal of the activity of hydrogen ions (in moles per litre).
? A pH of 7 corresponds to a neutral solution, one less than 7 to an acidic solution, and one greater than 7 to an alkaline solution.
pH-stat noun a device for automatically maintaining a solution at constant pH M20.