Henderson Hasselbalch Equation is used to describe the derivation of pH as a measure of acidity in biological and chemical systems. The basic equation is, h= -Log(k) + Log(b/a). Here, h is the pH value using Henderson Hasselbalch Formula, k is the Acid Dissociation Constant, b is the Molar Concentration of the Conjugate Base and a is the Molar Concentration of the Conjugate Acid.
Find the pH of a buffer solution formed from 0.5 kg/m3 acid and 0.2 kg/m3 base whose acid dissociation constant is 2.1 x 10-5.
pH = - log (2.1 x 10-5) + log (0.2 / 0.5)
= - log (2.1 x 10-5) + log(0.4)