In this activity students carry out a titration to determine the concentration of an acidic solution. The equivalence point can be determined from the titration curve. Compared to a “regular” titration, the use of an automated step motor burette adds an extra dimension to the experiment, allowing for addition of the base using constant speed. This experiment focusses on setting up the experiment and analysing the results.
Students learn to work with the gas chromatographer (BT45i) while doing this activity. They use hydrogen gas obtained from the Hofmann apparatus. This activity is easy and fast and helps students to master the BT45i so they can use the gas chromatographer for other more challenging activities. Hydrogen gas gives an easy to analyse chromatogram.
In this activity students study an existing model of an irreversible reaction of N2O4 to NO2 and expand it in order to create a chemical equilibrium. In order to teach students to critically assess a model, the concentration quotient has to be calculated at some point in the activity. This activity focusses on the essence of modelling and less on the workings of an equilibrium.
In this activity students study the reaction between magnesium and hydrochloric acid using a pre-recorded video. The reaction equation shows that a gas is produced. By measuring the amount of gas that is produced during a certain amount of time, the reaction rate can be determined. Students follow the rate of gas production by following the position of floating plastic balls in the collecting cylinder. By using the correct scaling, the moment of the balls can be correlated to a certain volume of gas. This scaling has already been prepared so that students can focus on the chemical aspects of this experiment.