Expression of uncertainty of an acid–base titration

Abstract

Uncertainty of measurement is a parameter of quality that should accompany any measurement result. The uncertainty estimation process is well defined in the literature; however, this concept is better understood and more easily applied through examples. In this paper a broadly used analytical procedure is discussed for the determination of the concentration of hydrochloric acid by titration against a standardized sodium hydroxide solution. The expanded uncertainty of the final result is expressed, endeavouring, in particular to evaluate covariances and to take into account the chemical behaviour of the specific reagents.