Determining the Density and Molar Mass of AIr in a Home Experiment

Formulation of the problem. Experimental research is an integral part of physics education. During distance learning, students can carry out hands-on experiments only at home. Modern smartphones, equipped with various sensors, offer significant capabilities for this purpose. The literature offers quite extensive descriptions of experiments aimed at determining mechanical, acoustic, and optical quantities using smartphones. At the same time, insufficient attention has been paid to determining gas parameters that can be measured using the pressure sensor embedded in smartphones. Therefore, the relevant task is to develop a methodology for experimenting to determine the density of air and its molar mass at home using a pressure sensor. Materials and methods. To achieve the objective of the study, we used the analysis of the curriculum of the course "General Physics for Bachelor of Engineering", a review of the methodological instructions for performing laboratory work in the section "Molecular Physics and Thermodynamics" of the physics course of technical universities, a review of the literature on the topic of the study, and an analysis of the results of student research on the dependence of air pressure on altitude. We also surveyed students about the possibility of conducting the research at home and their interest in conducting other experiments using a smartphone. Results. The methodology for determining the density and molar mass of air was developed based on the results of a study of the pressure-height dependence. It is shown that it is necessary to perform statistical processing of experimental data to estimate the sought quantities. The experimental results allowed us to obtain values of density and molar mass of air that show a good correlation with the tabulated values. Conclusions. Studying the pressure-altitude relationship using a smartphone and the PhyPhox application allows for fairly accurate calculations of air density and molar mass. According to the survey results, students responded positively to conducting home experiments using smartphones.