Equivalence-point location in the titration of a weak acid with sodium hydroxide solution: a comparison of photometric and potentiometric methods. Influence of titrant carbonation on the accuracy and precision of end-points

Abstract

Using standard laboratory equipment a statistical comparison was carried out of several photometric methods (normal and various Higuchi plots) and potentiometric methods (point of inflection and Gran) for equivalence-point location in an acetic acid-sodium hydroxide solution titration. All methods exhibited similar precision but were divided into two groups with respect to accuracy. With increasing carbonate concentration in the titrant there was a decrease in the linear range for Higuchi and Gran plots and a decrease in accuracy for all methods.