Experimental improvement of traditional gravimetry: take the determination of barium content in soluble barium salt as an example

To enhance the safety of experimental teaching, shorten the experimental duration, improve the teaching efficiency, and promote the concept of green chemistry, this study takes the determination of barium content in soluble barium salt as an example, a series of improvements have been made to the traditional gravimetric analysis experimental protocol. These improvements encompass precipitate preparation, filtration and precipitate ignition. For precipitate ignition, a microwave oven was employed as a replacement for the traditional muffle furnace. This study provides a detailed investigation of factors such as microwave power, constant-weight time, cooling time and the number of crucibles during the microwave heating process. The results demonstrate that the optimal conditions for constant-weight experiments are as follows: 4 crucibles in the microwave oven, a microwave power of 637.5 W (medium-high), an initial microwave heating time of 15 min, a secondary microwave heating time of 5 min, and a cooling time of 50 min. The improved experimental scheme is suitable for undergraduate experimental teaching, offering not only improved experimental efficiency but also reduced experimental hazards.