Abstract:

"Determining the heat of combustion" represents a familiar lab experiment that primarily provides a thermochemical understanding of combustion enthalpies. The experimental modification presented here is based on the practical production of commercial phthalic anhydride. Here, the reaction enthalpy is estimated by determining the heat of combustion of naphthalene, o-xylene, phthalic acid, and phthalic acid anhydride. This design may not only improve experimental contents but also strengthen practical applications of the heat of combustion. All required experimental reagents are cheap and readily available, and their heat of combustion can be measured accurately, making calculations of the overall reaction heat reliable. Moreover, a combined schedule of online and offline flipped learning will be implemented during the experiment; thus, enthalpy calculations for different reactions are expected to require cooperation among students. This modification may therefore be helpful for cultivating self-directed learning and teamwork among students.

Key words: Heat of combustion, Chemical reaction heat, Flipped learning, Improvement of experiment