The Royal Society of Chemistry has produced a booklet entitled ‘Microscale Chemistry’ (http://pubs.rsc.org/en/content/ebook/9781870343497#!divbookcontent). Microscale chemistry has been around for 20 or so years but many teachers are not aware of it or its teaching implications.
What is it? Well, it is chemistry on the small scale! When I first found out about it I was a bit sceptical – why would I wish to tone down my teaching and make it smaller – surely I should be making it bigger!
However, after reading about the concept and seeing it in action I was sold. It allows the teacher to carry out lab work with students that they wouldn’t usually consider or do – for example, letting students investigate the reactions of nitrogen dioxide (too dangerous) or looking at how carbon dioxide reacts (too difficult).
How does it work? You will need lots of plastic dropping pipettes, petri dishes and OHP (remember those?!) transparencies – or acetate plastic or similar.
The dropping pipette teat is cut to form a mini dish and many reactions are carried out in petri dishes or on acetate paper. For example, nitrogen dioxide can be made reacting concentrated nitric acid with copper turnings – dangerous on the large scale but using your miscroscale set you can set the experiment up as follows:
1, Put your mini dish in the centre of a petri dish – ensure the lid can be put on the petri dish without squashing the end of the pipette.
2, Then add literally three or four drops of conc. acid onto some of the copper turnings.
3, Seal the unit by putting the lid on the petri dish.
Substances such as Potassium Iodide can be put around the edge of the petri dish and one can observe what happens when the nitrogen dioxide diffuses to the potassium iodide.
If you like, this is just the simple version (entry level version) of the kit you need – more specific pieces of equipment can also be purchases (such as simple fuel burners, test tubes, etc) but I would always recommend trying the simple stuff before spending money of the specialist equipment.I hate to write this but I do need to point out that as the teacher in charge of any class, whatever level of work you use (macro or microscale), you are responsible for your own risk assessments and safety.
At the start of this post I wrote about the RSC publication – ‘Microscale Chemistry’ – if, after reading the post you are still not convinced, you may wish to have a look at the three links below – these take you to some of the microscale practical’s offered in the book and give you more of an idea of what they are about.
As ever, I’d love to hear of your experiences, be it good, bad or ideas for other microscale labs.