A large number of students experience difficulty detecting the endpoint of tritrations using some visual indicators due to the subtle color change of the indicator. We have devised an inexpensive and simple apparatus using a miniature pump, vinyl tubing, and a test tube to monitor the course of the titration spectrophotometrically using a Spectronic 20 spectrophotometer. It allows the determination of the equivalence point accurately and removes the error caused by the subjective nature of the visual endpoint. Sample results obtained by students, which demonstrate the successful inclusion of the apparatus in the analytical chemistry laboratory, are given.
Indralingam et al. (Tue,) studied this question.