Use large scale diagrams with many molecules to show the progression from initial to reacting to equilibrium, and extend that with changes to the system that influence the equilibrium. In these ensure that there are many molecules present rather than one.
Use demonstration or simulation of how both forward and reverse reactions occur up to and at equilibrium in several mixtures. The PhET simmulation below shows both reactions are happening, even though concentration of reactants and products isn't changing.
Put a bit more emphasis on the physical state of the substance that they are learning about. Because students often aren’t really able to imagine what kind of substance they are going to learn about. They will then know that they don’t have to calculate the volume if it’s a solid, for example, they have to calculate it by mass.
Put zinc metal in copper sulphate solution and record it with the visualiser. Have it running as you talk about the push and pull of electrons. Then bring it up and say, ‘look what’s happened here, the zinc has rusted’. Students make more of a link when they see things being visualised. The oxidation of metal has a very visual impact on them. But then, they might forget about the reduction side, so you need to remind them of it.
Students’ ability to visualise the molecules in free space is limited sometimes. So a strategy is to ask the students to take out their smart phone and use it as a mirror by putting it opposite the molecule on the paper, so that they can see the reflection and easily visualise the molecule. This is good for teaching enantiomers and rotating the molecule.
Particularly for the VSEPR theory, models of any kind are great. Tell the students, 'Buy a model kit.' Because it has to be something three-dimensional. They need to bring their own models in so they can do it themselves.
3D modelling software is very good. There are some Java Applets that show 3D visualisations of orbitals. You just select whichever orbital you want and you can rotate it and view it from different angles.
For this particular topic, there are some quite nice simulations of wave functions and of orbitals and similar things on the web that can be used to visualise what orbitals look like, and what wave functions look like. They seem to like it.
Use balloons to illustrate bonding pairs and electron pair repulsions leading to the determination of molecular shape For example, if you tie 6 balloons together, it automatically forms the octahedral shape. Then each time you pop one, they rearrange themselves to sequentially form the other shapes: trigonal bipyramidal, tetrahedral, trigonal planar and linear. It’s visually appealing, a concrete example and memorable for students. Also, popping the balloons wakes the students up!
