Resolving Complex Chemical Processes: Comparison of Monitoring by Ultrasound with Other Measurement Methods

A weak acid-strong base time-resolved titration has been monitored by ultrasonic and pH measurements. Various treatments have been applied to the acquired data, and the results obtained are presented and discussed. It has been found that the group velocity of ultrasound is the most robust parameter after enhancement of the time resolution of the ultrasonic hardware by signal processing. Application of temperature correction transformed the ultrasonic titration curves into two nearly straight lines that intersect at the equivalence point of the titration at the maximum point on the curve. The ultrasonic instrument exhibited much lower stabilisation times after titrant addition compared to the conventional pH-meter making ultrasonic spectroscopy potentially very useful for monitoring/controlling fast chemical processes including acid-base reactions