Abstract This lesson takes food self-heating bag as the theme, reviews the properties and uses of acids and bases by analyzing the components of the self-heating bag, deciphering the heating principle, calculating the proportion of raw materials, preparing self-heating bags. From the perspective of transformation view and element view to understand the law of material transformation, the general ideas of material research and the basic process of scientific inquiry are highlighted and shown. The methods of composition identification and quantitative determination of the mixture are summarized through the design of experimental scheme to determine the content of sodium carbonate in the self-heating bag. The influencing factors of gas quantitative determination are summarized. This paper presents a specific teaching example of subject concept and subject method, and highlights the basic methods of material research, qualitative inspection and quantitative determination.
REN Xiao-Meng. Creative Teaching of “Properties of Acids and Bases” in Junior High School Chemistry: Analysis of Food Self-Heating Bag[J]. Chinese Journal of Chemical Education, 2022, 43(9): 25-30.
