Development of the kinetic molecular theory of gases concept inventory: Preliminary results on university students’ misconceptions

In this study, we investigated students’ understanding of concepts related to the microscopic model of gas. We thoroughly reviewed the relevant literature and conducted think alouds with students by asking them to answer open-ended questions about the kinetic molecular theory of gases. Thereafter, we transformed the open-ended questions into multiple-choice questions, whereby distractors were based on the results of the think alouds. Thus, we obtained a set of 22 questions, which constitutes our current version of the kinetic molecular theory of gases concept inventory. The inventory has been administered to 250 students from different universities in Croatia, and its content validity has been investigated trough physics teacher surveys. The results of our study not only corroborate the existence of some already known student misconceptions, but also reveal new insights about a great spectrum of students’ misconceptions that had not been reported in earlier research (e.g., misconceptions about intermolecular potential energy and molecular velocity distribution). Moreover, we identified similar distribution of students’ responses across the surveyed student groups, despite the fact that they had been enrolled in different curricular environments.

Figure 1

The students’ responses to the concept inventory multiple choice (A–E) questions (Tasks 1, 2, 5, and 6), grouped by the gas structure concept concerned. Results for each question are presented by five bar diagrams, each containing the total sample ($N=250$) result ALL and the results from all the test groups (MED, EIT, EDU, and RES). The correct answers are presented by the black bars.

Figure 2

The students’ responses to the task referring to the gas volume concept. For a detailed description see Fig. 1.

Figure 3

The students’ responses to the task referring to the gas pressure concept. For a detailed description see Fig. 1.

Figure 4

The students’ responses to the tasks grouped by the intermolecular potential energy concept concerned. For a detailed description see Fig. 1.

Figure 5

The students’ responses to the tasks grouped by the kinetic energy of gas molecules concept concerned. For a detailed description see Fig. 1.

Figure 6

The students’ responses to the tasks grouped by the gas temperature concept concerned. For a detailed description see Fig. 1.

Figure 7

The students’ responses to the task referring to the molecular velocity concept. For a detailed description see Fig. 1.

Figure 8

The students’ responses to the tasks grouped by the thermal internal energy of a gas concept concerned. For a detailed description see Fig. 1.

Figure 9

The students’ responses to the tasks grouped by the gas entropy concept concerned. For a detailed description see Fig. 1.

Figure 10

First page of the kinetic molecular theory of gases concept inventory.

Figure 11

Second page of the kinetic molecular theory of gases concept inventory.

Figure 12

Third page of the kinetic molecular theory of gases concept inventory.