Magnesium and Hydrochloric Acid
Magnesium reacts with hydrochloric acid to produce hydrogen. The gas is collected in a syringe and its volume is recorded as a function of time. From the measured data, learners determine the amount of hydrogen produced as well as the change in hydronium ion concentration and plot the reaction progress in a concentration–time graph. On this basis, the average reaction rate is determined quantitatively.
As an extension, learners investigate how the form and resulting surface area of the magnesium affect the reaction rate. Magnesium ribbon, magnesium shavings, and magnesium powder are reacted under comparable conditions and the reaction times are compared. The results are then explained using collision theory and the differences in available surface area.
The simulation extends the real experiment by adding an interactive, model-based perspective. Learners can vary the mass of magnesium and choose between magnesium ribbon, magnesium shavings, and magnesium powder. This allows them to investigate how the amount of substance and available surface area affect the course of the reaction and the formation of hydrogen.
During the simulation, reaction time and hydrogen volume are recorded continuously and displayed in a volume–time graph. Experimental data from the real experiment can also be entered directly into the application. The simulation uses these data to calculate the amount of hydrogen produced as well as the remaining amount and concentration of hydronium ions and displays the results in a concentration–time graph.
The particular educational value lies in the comparison of the real experiment, experimental data, and simulation. Differences between experimental and simulated results become the starting point for questions about experimental conditions, model assumptions, and the limitations of the simulation. Learners are therefore asked not only to describe and analyse results, but also to explain, justify, compare, and evaluate them — extending the learning process into higher-order thinking.
The simulation does not replace the real experiment. Instead, it expands its potential for scientific inquiry. It can be integrated directly into an experimental lesson, used for preparation or follow-up, or embedded in blended and hybrid learning environments. In this way, the real experiment and the simulation become integral and immersive components of a coherent scientific inquiry process.