You can get the concept of: The real and potential electrolytes, strong and weak acids, equation Henderson-Hasselbalch, dissociation constant and the value of pKa, Photometry.
Principle: Carboxylic acids - potential electrolytes, which show a weak degree of dissociation in aqueous solutions. Location dissociative equilibrium is quantitatively described in terms of the Ka or the value of pKa, which may be determined by potentiometric measurements.