To emphasise the quantitative aspect of the first order decay process, you can use a demonstration on the visualizer – take 40 M&Ms and place them face up (the ‘M’ up) in a clear Tupperware container. This is the population at t=0. Ask a student volunteer to come and shake the container (gently) for 3 seconds and remove the M&Ms that are now face down – the remaining population is recorded as t1/2 on a graph.
The ChemBytes website has a sophisticated set of learning resources for chemical equilibrium. Simulations and practice problems are integrated to help students understand the basics.
The ChemBytes website has a sophisticated set of learning objects to help students understand specific fundamental topics such as aqueous solutions. Dissolution and speciation are covered in detail with simulations and visualisations.
We all spend a certain amount of our class time going through definitions and jargon and getting students up to speed with the basic area and now that’s material which I take out of the class and put online and let students read and understand that in their own time before they come to the class.
A visual demonstration of Le Chatelier’s principle involves the dynamic equilibrium between nitrogen dioxide and dinitrogen tetroxide gases. Fill a gas syringe with an equilibrium mixture of brown NO2 and colourless N2O4. The effect of pressure is shown by compressing the mixture and observing the change in colour intensity. Similarly, the effect of temperature can be shown by heating or cooling the mixture and observing the colour change.
