the normality of a solution with respect to hydrogen ions, H+; it is related to acidity measurements in most cases by the equation pH= log 1/2[1/(H+)] where H+ is the hydrogen ion concentration in gram equivalents per liter of solution.
the degree of concentration of hydrogen ions in a solution; it is inversely related to the pH of the solution and can be expressed by the equation [H+] = 10−pH.
a measure of the acidity or alkalinity of a solution expressed as pH. See pH. 
the normality of a solution with respect to hydrogen ions, H+; it is related to acidity measurements in most cases by the equation pH= log 1/2[1/(H+)] where H+ is the hydrogen ion concentration in gram equivalents per liter of solution.
[n] - the number of moles of hydrogen ions per cubic decimeter
noun the number of moles of hydrogen ions per cubic decimeter