pH
pH
noun \(ˈ)pē-ˈāch\Definition of PH
: a measure of acidity and alkalinity of a solution that is a number on a scale on which a value of 7 represents neutrality and lower numbers indicate increasing acidity and higher numbers increasing alkalinity and on which each unit of change represents a tenfold change in acidity or alkalinity and that is the negative logarithm of the effective hydrogen-ion concentration or hydrogen-ion activity in gram equivalents per liter of the solution <instead of saying that the concentration of hydrogen ion in pure water is 1.00 x 10−7, it is customary to say that the pH of pure water is 7—Linus Pauling>; also : the condition represented by such a number—compare pk
