| 摘要 |
PURPOSE:To measure the reaction process and final point of the redox reaction, substitution reaction or precipitate-forming reaction of org. and inorg. compounds with good accuracy, by adapting a potential difference titration method or a current titration method by using an electrode of which the detection part is constituted of gold. CONSTITUTION:A diazo reaction or azo coupling reaction system, for example, an aqueous solution containing 2,6-dichloro-4-nitroaniline and sulfuric acid is introduced into a container 1 receiving a solution to be titrated. A bipolar electrode equipped with detection parts 2, 3 made of gold for detecting potential change with the advance of reaction is immersed in the container 1. Subsequently, a minute current is passed to the electrode from a DC power source 4 and potential change corresponding to the consumption of a titration reagent, for example, sodium nitrite cyclically added from a buret 6 is recorded by a potentiometer 5 to measure the final point of reaction. The excessive quantity of sodium nitrite being an oxidizing agent can be sufficiently grasped as potential change by this measurement. Therefore, a final point can be measured with good sensitivity and a reaction process is monitored and the speed of objective reaction can be adjusted. |
