Students from high school might understand that vinegar for example is a weak acid compared to hydrochloric acid, but they never knew why. And you could then show them that with equilibrium, this is why. And all of a sudden they’re, 'oh, I’ve always known that I shouldn’t spill HCL on my hand, but I can spill vinegar on my hand and put it on my fish and chips'... Those sorts of moments can really... the students go ‘oh wow.’
Start to flag the concept of equilibrium early when teaching other topics, saying this is the concept of equilibrium we’ve got to come to later. So students start to understand how it’s all interlinked, rather than it being a lone, odd concept?
Compare the material to what they might be learning in physics. For example, in Le Chatelier’s principle, a phrase like ‘counteract the change’ is similar to Lens’s Law in physics for electromagnetic induction. So maybe if students have a better grip of that they can see similarities there. It’s trying to draw that bridge. If the students aren’t doing physics you can always draw something from maths or something from biology.
Interconnect equilibrium with other topics – acid-base, reaction rates etc. You can introduce part of the topic of weak and strong acids and then do a bit of equilibrium, just enough to make sense of it.
It’s really important always to keep going back to links of where they might have seen equilibrium previously, because then they start to get the idea of chemistry topics being interrelated. Even put at the end of each lecture a little problem, for example, ‘how is equilibrium related to acids and bases?’ Even if they don’t understand it yet, just mention it so it’s in the back of their mind when they do learn about that topic.
You rarely see organic reactions split up into two half equations. You could show the link between redox and organic chemistry by getting them to write the half equations for reactions like the oxidation of an aldehyde, ketone or alcohol with permanganate, for example. You want them to realise that it goes from purple to colourless then they have to write it out.
Link this topic to organic reactions since a lot of them are actually acid/base reactions. That is, there is one species that’s electron rich and one that’s electron poor.
Relate equilibrium to students’ own experience of strong versus weak acids. For example, you can put vinegar on your fish and chips but not HCl. From high school they might have an understanding that vinegar is a weak acid compared to hydrochloric acid, but they never knew why. And you could then show them that with equilibrium, this is why.
Explain partial charges, with problems, then link this to bond polarity. Explain the differences in arrows 'language'. Draw organic structures as line structures and no stereochemistry (until you discuss that). Make stoichiometry explicit and link the structures to names to build on the concepts.
The nature of the students is that there are some that are interested in this topic in its own right. But many of them want to end up doing organic chemistry and pharmacology, or medicine of some sort. This is a theory which is too much physics for some of them, so you’ve always got to relate it back to their own interests.
