Photometric investigation of precipitation titrations

Photometric investigation of precipitation reactions, by automatically recording the changes in absorbance of a stirred suspension with titrant added, showed that end-points and reacting mole ratios are quickly and easily evaluated. Quantitative analysis in the concentration range 10^-2 to 10^-4M is possible with an error of about 1%. The use of breaks in titration curves to formulate intermediate reaction products is doubtful. A rapid change in the physical form of the precipitate is a limitation of the method.